Bifunctional Precision PEG

HO-PEG-OH

Alpha,omega-dihydroxy Poly(ethylene glycol); Discrete Poly(ethylene glycol) Diol (HO-PEG-OH) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear hydroxyl groups. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation. Customization available.

H2N-PEG-NH2

Alpha,omega-diamino poly(ethylene glycol) (H2N-PEG-NH2) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear primary amine groups. Discrete chain lengths with different degrees of polymerization are available. The primary amine can react with activated carboxyl groups or NHS esters to form amide bonds and introduce carboxyl-containing functional moieties. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Amide-based bioconjugation; Peptide and functional small-molecule conjugation; Amino-PEG derivatization. Customization available.

HS-PEG-SH

Alpha,omega-dithiol poly(ethylene glycol) (HS-PEG-SH) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear thiol groups. Discrete chain lengths with different degrees of polymerization are available. The thiol can add to maleimides or participate in disulfide formation, offering different molecular conjugation routes. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Thiol-selective conjugation; Disulfide-linkage design; Surface anchoring and crosslinked materials. Customization available.

HO-PEG-NH2

Alpha-(hydroxy)-omega-(amino) poly(ethylene glycol) (HO-PEG-NH2) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and primary amine groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The primary amine can react with activated carboxyl groups or NHS esters to form amide bonds and introduce carboxyl-containing functional moieties. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Amide-based bioconjugation; Peptide and functional small-molecule conjugation; Amino-PEG derivatization. Customization available.

HO-PEG-SH

Alpha-(hydroxy)-omega-(sulfanyl) poly(ethylene glycol) (HO-PEG-SH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and thiol groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The thiol can add to maleimides or participate in disulfide formation, offering different molecular conjugation routes. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Thiol-selective conjugation; Disulfide-linkage design; Surface anchoring and crosslinked materials. Customization available.

HO-PEG-CH2COOH

Alpha-(hydroxy)-omega-(carboxymethyl) poly(ethylene glycol) (HO-PEG-CH2COOH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and carboxymethyl groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The carboxymethyl group can be activated for coupling with primary amines. Its single methylene group defines the local connection between the reactive carboxyl group and the polyether chain. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Carboxymethyl-PEG derivatization; Amide-linker synthesis; Local spacing studies at reactive termini. Customization available.

HO-PEG-CH2CH2COOH

Alpha-(hydroxy)-omega-(carboxyethyl) poly(ethylene glycol) (HO-PEG-CH2CH2COOH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and carboxyethyl groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The carboxyethyl group can be activated to couple with amine-containing components. Its two methylene groups provide a local spacer distinct from a carboxymethyl linker. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Extended carboxylic acid linkers; Amine-containing ligand conjugation; Local spacer structure–activity comparisons. Customization available.

HO-PEG-NHFmoc

Alpha-(hydroxy)-omega-(fluorenylmethoxycarbonyl-protected amino) poly(ethylene glycol) (HO-PEG-FmocNH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and Fmoc-protected amine groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. Fmoc protection facilitates sequential conjugation. Amine coupling can follow deprotection under conditions compatible with the target system. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Orthogonal protection and linker synthesis; Peptide conjugation intermediates; Sequential amine functionalization. Customization available.

HO-PEG-NHCbz

Alpha-(hydroxy)-omega-(benzyloxycarbonyl-protected amino) poly(ethylene glycol) (HO-PEG-CbzNH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and Cbz-protected amine groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The Cbz-protected end retains a releasable amine precursor, allowing amine coupling and transformations at the other terminus to be performed sequentially. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Protected amino linkers; Sequential end-group transformations; Functional molecular module synthesis. Customization available.

HO-PEG-ONH2

Alpha-(hydroxy)-omega-(aminooxy) poly(ethylene glycol) (HO-PEG-ONH2) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and aminooxy groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The aminooxy group can condense with aldehydes or ketones to form oxime bonds, providing a conjugation route for carbonyl-containing molecules and carriers. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Oxime ligation; Carbonyl-site labeling; Glycan and functional-probe conjugation. Customization available.

HO-PEG-OTs

Alpha-(hydroxy)-omega-(p-toluenesulfonate) poly(ethylene glycol) (HO-PEG-OTs) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and tosylate groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The tosylate acts as a leaving group, enabling nitrogen- or sulfur-containing functional moieties to be introduced by nucleophilic substitution. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; PEG end-group conversion; Nucleophilic substitution intermediates; Linker extension. Customization available.

HO-PEG-OMs

Alpha-(hydroxy)-omega-(methanesulfonate) poly(ethylene glycol) (HO-PEG-OMs) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and mesylate groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The mesylate provides a handle for nucleophilic substitution, allowing chain-segment construction and installation of the final functional terminus to be performed separately. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; End-group nucleophilic substitution; Functional PEG synthesis; Chain-extension intermediates. Customization available.

HO-PEG-Cl

Alpha-(hydroxy)-omega-(chloro) poly(ethylene glycol) (HO-PEG-Cl) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and chloro group groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The chloro terminus can serve as a precursor for suitable nucleophilic substitution reactions to introduce target functional moieties. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Halogenated PEG derivatization; Nucleophilic substitution intermediates; Chain-segment conjugation studies. Customization available.

HO-PEG-Br

Alpha-(hydroxy)-omega-(bromo) poly(ethylene glycol) (HO-PEG-Br) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and bromo group groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The bromo terminus retains a handle for subsequent nucleophilic substitution, facilitating the introduction of nitrogen- or sulfur-containing linking moieties. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Bromo end-group conversion; Linker synthesis; Installation of functional moieties. Customization available.

HO-PEG-I

Alpha-(hydroxy)-omega-(iodo) poly(ethylene glycol) (HO-PEG-I) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and iodo group groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The iodo terminus can be used in suitable nucleophilic substitution routes, enabling comparisons of different halogenated linker precursors and their derivatives. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Iodo-PEG intermediates; Terminal substitution reactions; Functional-molecule synthesis. Customization available.

HO-PEG-OAc

Alpha-(hydroxy)-omega-(acetoxy) poly(ethylene glycol) (HO-PEG-OAc) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and acetoxy groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The acetate temporarily masks the hydroxyl group. Appropriate deprotection restores the opportunity for further hydroxyl derivatization. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Hydroxyl protection and deprotection; Sequential PEG derivatization; Acetate-linkage structure studies. Customization available.

HO-PEG-Acrylate

Alpha-(hydroxy)-omega-(acrylate) poly(ethylene glycol) (HO-PEG-Acrylate) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and acrylate groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The acrylate double bond can participate in radical polymerization or suitable thiol addition reactions to introduce a polymerizable PEG segment. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Polymerizable PEG monomers; Thiol-addition conjugation; Hydrogel and crosslinked-network studies. Customization available.

HO-PEG-Methacrylate

Alpha-(hydroxy)-omega-(methacrylate) poly(ethylene glycol) (HO-PEG-Methacrylate) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and methacrylate groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The methacrylate can undergo radical polymerization or copolymerization, covalently incorporating the PEG segment into polymer materials. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Functional PEG monomers; Hydrophilic copolymer materials; Crosslinked networks and surface grafting. Customization available.

HO-PEG-VinylEther

Alpha-(hydroxy)-omega-(vinyl ether) poly(ethylene glycol) (HO-PEG-VinylEther) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and vinyl ether groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The vinyl ether retains a double bond available for polymerization or addition in compatible chain-segment polymerization and functionalization routes. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Vinyl ether polymerization; Reactive hydrophilic segments; Functional-material synthesis. Customization available.

HO-PEG-Allyl

Alpha-(hydroxy)-omega-(allyl ether) poly(ethylene glycol) (HO-PEG-Allyl) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and allyl ether groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The allyl group can participate in thiol–ene reactions or suitable alkene transformations, providing a conjugation handle for thiol-containing modules. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Thiol–ene conjugation; Alkenyl-functional PEG; Crosslinked materials and surface modification. Customization available.

HO-PEG-CH2COOtBu

Alpha-(hydroxy)-omega-(tert-butyl-protected carboxymethyl) poly(ethylene glycol) (HO-PEG-CH2COOtBu) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and tert-butyl-ester-protected carboxymethyl groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The tert-butyl ester temporarily protects a carboxyl precursor. Appropriate acidic deprotection enables subsequent carboxyl activation and amide coupling. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Protected carboxylic acid linkers; Sequential end-group conjugation; PEG synthetic intermediates. Customization available.

HO-PEG-CH2COOMe

Alpha-(hydroxy)-omega-(methyl-protected carboxymethyl) poly(ethylene glycol) (HO-PEG-CH2COOMe) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and methyl-ester-protected carboxymethyl groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The methyl ester remains available for subsequent ester transformations, allowing a conjugatable carboxyl group to be introduced after other linking steps. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Carboxylic acid precursor synthesis; Sequential PEG derivatization; Ester-linker conversion. Customization available.

HO-PEG-Glycidyl

Alpha-(hydroxy)-omega-(glycidyl ether) poly(ethylene glycol) (HO-PEG-Glycidyl) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and glycidyl ether groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The epoxide can undergo ring-opening addition with suitable nucleophiles, such as amines or thiols, for subsequent segment linking and material crosslinking. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Epoxide ring-opening conjugation; Amine- and thiol-containing material conjugation; Functional polyether synthesis. Customization available.

HO-PEG-NHMe

Alpha-(hydroxy)-omega-(methylamino) poly(ethylene glycol) (HO-PEG-NHMe) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and methylamino groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The secondary amine can participate in suitable acylation or other amine reactions, enabling comparisons of amine substitution and conjugation routes. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Secondary-amine PEG derivatization; N-substituted linker synthesis; Amine-terminus structure comparisons. Customization available.

HO-PEG-NMe2

Alpha-(hydroxy)-omega-(dimethylamino) poly(ethylene glycol) (HO-PEG-NMe2) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and dimethylamino groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The tertiary amine provides sites for acid–base and ionic interactions, enabling studies of terminal charge presentation in different media. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Tertiary-amine-terminated functional materials; Acid–base response studies; Interfacial charge adjustment. Customization available.

H2N-PEG-SH

Alpha-(amino)-omega-(sulfanyl) poly(ethylene glycol) (H2N-PEG-SH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear primary amine and thiol groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The primary amine can react with activated carboxyl groups or NHS esters to form amide bonds and introduce carboxyl-containing functional moieties. The thiol can add to maleimides or participate in disulfide formation, offering different molecular conjugation routes. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Amide-based bioconjugation; Peptide and functional small-molecule conjugation; Amino-PEG derivatization; Thiol-selective conjugation; Disulfide-linkage design; Surface anchoring and crosslinked materials. Customization available.

H2N-PEG-CH2COOH

Alpha-(amino)-omega-(carboxymethyl) poly(ethylene glycol) (H2N-PEG-CH2COOH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear primary amine and carboxymethyl groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The primary amine can react with activated carboxyl groups or NHS esters to form amide bonds and introduce carboxyl-containing functional moieties. The carboxymethyl group can be activated for coupling with primary amines. Its single methylene group defines the local connection between the reactive carboxyl group and the polyether chain. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Amide-based bioconjugation; Peptide and functional small-molecule conjugation; Amino-PEG derivatization; Carboxymethyl-PEG derivatization; Amide-linker synthesis; Local spacing studies at reactive termini. Customization available.

H2N-PEG-NHBoc

Alpha-(amino)-omega-(tert-butoxycarbonyl-protected amino) poly(ethylene glycol) (H2N-PEG-BocNH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear primary amine and Boc-protected amine groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The primary amine can react with activated carboxyl groups or NHS esters to form amide bonds and introduce carboxyl-containing functional moieties. Boc protection separates amine reactions from other synthetic steps. Appropriate deprotection exposes a primary amine for subsequent conjugation. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Amide-based bioconjugation; Peptide and functional small-molecule conjugation; Amino-PEG derivatization; Protected PEG linkers; Sequential bioconjugation synthesis; Primary-amine precursor construction. Customization available.

H2N-PEG-NHFmoc

Alpha-(amino)-omega-(fluorenylmethoxycarbonyl-protected amino) poly(ethylene glycol) (H2N-PEG-FmocNH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear primary amine and Fmoc-protected amine groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The primary amine can react with activated carboxyl groups or NHS esters to form amide bonds and introduce carboxyl-containing functional moieties. Fmoc protection facilitates sequential conjugation. Amine coupling can follow deprotection under conditions compatible with the target system. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Amide-based bioconjugation; Peptide and functional small-molecule conjugation; Amino-PEG derivatization; Orthogonal protection and linker synthesis; Peptide conjugation intermediates; Sequential amine functionalization. Customization available.

H2N-PEG-NHCbz

Alpha-(amino)-omega-(benzyloxycarbonyl-protected amino) poly(ethylene glycol) (H2N-PEG-CbzNH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear primary amine and Cbz-protected amine groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The primary amine can react with activated carboxyl groups or NHS esters to form amide bonds and introduce carboxyl-containing functional moieties. The Cbz-protected end retains a releasable amine precursor, allowing amine coupling and transformations at the other terminus to be performed sequentially. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Amide-based bioconjugation; Peptide and functional small-molecule conjugation; Amino-PEG derivatization; Protected amino linkers; Sequential end-group transformations; Functional molecular module synthesis. Customization available.

H2N-PEG-CH2COOtBu

Alpha-(amino)-omega-(tert-butyl-protected carboxymethyl) poly(ethylene glycol) (H2N-PEG-CH2COOtBu) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear primary amine and tert-butyl-ester-protected carboxymethyl groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The primary amine can react with activated carboxyl groups or NHS esters to form amide bonds and introduce carboxyl-containing functional moieties. The tert-butyl ester temporarily protects a carboxyl precursor. Appropriate acidic deprotection enables subsequent carboxyl activation and amide coupling. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Amide-based bioconjugation; Peptide and functional small-molecule conjugation; Amino-PEG derivatization; Protected carboxylic acid linkers; Sequential end-group conjugation; PEG synthetic intermediates. Customization available.

H2N-PEG-CH2COOMe

Alpha-(amino)-omega-(methyl-protected carboxymethyl) poly(ethylene glycol) (H2N-PEG-CH2COOMe) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear primary amine and methyl-ester-protected carboxymethyl groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The primary amine can react with activated carboxyl groups or NHS esters to form amide bonds and introduce carboxyl-containing functional moieties. The methyl ester remains available for subsequent ester transformations, allowing a conjugatable carboxyl group to be introduced after other linking steps. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Amide-based bioconjugation; Peptide and functional small-molecule conjugation; Amino-PEG derivatization; Carboxylic acid precursor synthesis; Sequential PEG derivatization; Ester-linker conversion. Customization available.

HS-PEG-CH2COOH

Alpha-(sulfanyl)-omega-(carboxymethyl) poly(ethylene glycol) (HS-PEG-CH2COOH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear thiol and carboxymethyl groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The thiol can add to maleimides or participate in disulfide formation, offering different molecular conjugation routes. The carboxymethyl group can be activated for coupling with primary amines. Its single methylene group defines the local connection between the reactive carboxyl group and the polyether chain. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Thiol-selective conjugation; Disulfide-linkage design; Surface anchoring and crosslinked materials; Carboxymethyl-PEG derivatization; Amide-linker synthesis; Local spacing studies at reactive termini. Customization available.

HS-PEG-CH2CH2COOH

Alpha-(sulfanyl)-omega-(carboxyethyl) poly(ethylene glycol) (HS-PEG-CH2CH2COOH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear thiol and carboxyethyl groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The thiol can add to maleimides or participate in disulfide formation, offering different molecular conjugation routes. The carboxyethyl group can be activated to couple with amine-containing components. Its two methylene groups provide a local spacer distinct from a carboxymethyl linker. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Thiol-selective conjugation; Disulfide-linkage design; Surface anchoring and crosslinked materials; Extended carboxylic acid linkers; Amine-containing ligand conjugation; Local spacer structure–activity comparisons. Customization available.

HS-PEG-NHBoc

Alpha-(sulfanyl)-omega-(tert-butoxycarbonyl-protected amino) poly(ethylene glycol) (HS-PEG-BocNH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear thiol and Boc-protected amine groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The thiol can add to maleimides or participate in disulfide formation, offering different molecular conjugation routes. Boc protection separates amine reactions from other synthetic steps. Appropriate deprotection exposes a primary amine for subsequent conjugation. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Thiol-selective conjugation; Disulfide-linkage design; Surface anchoring and crosslinked materials; Protected PEG linkers; Sequential bioconjugation synthesis; Primary-amine precursor construction. Customization available.

HS-PEG-NHFmoc

Alpha-(sulfanyl)-omega-(fluorenylmethoxycarbonyl-protected amino) poly(ethylene glycol) (HS-PEG-FmocNH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear thiol and Fmoc-protected amine groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The thiol can add to maleimides or participate in disulfide formation, offering different molecular conjugation routes. Fmoc protection facilitates sequential conjugation. Amine coupling can follow deprotection under conditions compatible with the target system. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Thiol-selective conjugation; Disulfide-linkage design; Surface anchoring and crosslinked materials; Orthogonal protection and linker synthesis; Peptide conjugation intermediates; Sequential amine functionalization. Customization available.

HS-PEG-NHCbz

Alpha-(sulfanyl)-omega-(benzyloxycarbonyl-protected amino) poly(ethylene glycol) (HS-PEG-CbzNH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear thiol and Cbz-protected amine groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The thiol can add to maleimides or participate in disulfide formation, offering different molecular conjugation routes. The Cbz-protected end retains a releasable amine precursor, allowing amine coupling and transformations at the other terminus to be performed sequentially. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Thiol-selective conjugation; Disulfide-linkage design; Surface anchoring and crosslinked materials; Protected amino linkers; Sequential end-group transformations; Functional molecular module synthesis. Customization available.

HS-PEG-CH2COOtBu

Alpha-(sulfanyl)-omega-(tert-butyl-protected carboxymethyl) poly(ethylene glycol) (HS-PEG-CH2COOtBu) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear thiol and tert-butyl-ester-protected carboxymethyl groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The thiol can add to maleimides or participate in disulfide formation, offering different molecular conjugation routes. The tert-butyl ester temporarily protects a carboxyl precursor. Appropriate acidic deprotection enables subsequent carboxyl activation and amide coupling. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Thiol-selective conjugation; Disulfide-linkage design; Surface anchoring and crosslinked materials; Protected carboxylic acid linkers; Sequential end-group conjugation; PEG synthetic intermediates. Customization available.

HS-PEG-CH2COOMe

Alpha-(sulfanyl)-omega-(methyl-protected carboxymethyl) poly(ethylene glycol) (HS-PEG-CH2COOMe) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear thiol and methyl-ester-protected carboxymethyl groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The thiol can add to maleimides or participate in disulfide formation, offering different molecular conjugation routes. The methyl ester remains available for subsequent ester transformations, allowing a conjugatable carboxyl group to be introduced after other linking steps. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Thiol-selective conjugation; Disulfide-linkage design; Surface anchoring and crosslinked materials; Carboxylic acid precursor synthesis; Sequential PEG derivatization; Ester-linker conversion. Customization available.

CH2COOH-PEG-NHBoc

Alpha-(carboxymethyl)-omega-(tert-butoxycarbonyl-protected amino) poly(ethylene glycol) (HOOCCH2-PEG-NHBoc) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear carboxymethyl and Boc-protected amine groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The carboxymethyl group can be activated for coupling with primary amines. Its single methylene group defines the local connection between the reactive carboxyl group and the polyether chain. Boc protection separates amine reactions from other synthetic steps. Appropriate deprotection exposes a primary amine for subsequent conjugation. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Carboxymethyl-PEG derivatization; Amide-linker synthesis; Local spacing studies at reactive termini; Protected PEG linkers; Sequential bioconjugation synthesis; Primary-amine precursor construction. Customization available.

CH2COOH-PEG-NHCbz

Alpha-(carboxymethyl)-omega-(benzyloxycarbonyl-protected amino) poly(ethylene glycol) (HOOCCH2-PEG-NHCbz) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear carboxymethyl and Cbz-protected amine groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The carboxymethyl group can be activated for coupling with primary amines. Its single methylene group defines the local connection between the reactive carboxyl group and the polyether chain. The Cbz-protected end retains a releasable amine precursor, allowing amine coupling and transformations at the other terminus to be performed sequentially. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Carboxymethyl-PEG derivatization; Amide-linker synthesis; Local spacing studies at reactive termini; Protected amino linkers; Sequential end-group transformations; Functional molecular module synthesis. Customization available.

CH2COOH-PEG-CH2COOH

Alpha,omega-bis(carboxymethyl) poly(ethylene glycol) (HOOCCH2-PEG-CH2COOH) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear carboxymethyl groups. Discrete chain lengths with different degrees of polymerization are available. The carboxymethyl group can be activated for coupling with primary amines. Its single methylene group defines the local connection between the reactive carboxyl group and the polyether chain. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Carboxymethyl-PEG derivatization; Amide-linker synthesis; Local spacing studies at reactive termini. Customization available.

HOOCCH2CH2-PEG-CH2CH2COOH

Alpha,omega-bis(carboxyethyl) poly(ethylene glycol) (HOOCCH2CH2-PEG-CH2CH2COOH) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear carboxyethyl groups. Discrete chain lengths with different degrees of polymerization are available. The carboxyethyl group can be activated to couple with amine-containing components. Its two methylene groups provide a local spacer distinct from a carboxymethyl linker. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Extended carboxylic acid linkers; Amine-containing ligand conjugation; Local spacer structure–activity comparisons. Customization available.

CH2COOH-PEG-CH2CH2COOH

Alpha-(carboxymethyl)-omega-(carboxyethyl) poly(ethylene glycol) (HOOCCH2-PEG-CH2CH2COOH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear carboxymethyl and carboxyethyl groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The carboxymethyl group can be activated for coupling with primary amines. Its single methylene group defines the local connection between the reactive carboxyl group and the polyether chain. The carboxyethyl group can be activated to couple with amine-containing components. Its two methylene groups provide a local spacer distinct from a carboxymethyl linker. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Carboxymethyl-PEG derivatization; Amide-linker synthesis; Local spacing studies at reactive termini; Extended carboxylic acid linkers; Amine-containing ligand conjugation; Local spacer structure–activity comparisons. Customization available.

CH2COOH-PEG-CH2COOtBu

Alpha-(carboxymethyl)-omega-(tert-butyl-protected carboxymethyl) poly(ethylene glycol) (HOOCCH2-PEG-CH2COOtBu) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear carboxymethyl and tert-butyl-ester-protected carboxymethyl groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The carboxymethyl group can be activated for coupling with primary amines. Its single methylene group defines the local connection between the reactive carboxyl group and the polyether chain. The tert-butyl ester temporarily protects a carboxyl precursor. Appropriate acidic deprotection enables subsequent carboxyl activation and amide coupling. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Carboxymethyl-PEG derivatization; Amide-linker synthesis; Local spacing studies at reactive termini; Protected carboxylic acid linkers; Sequential end-group conjugation; PEG synthetic intermediates. Customization available.

CH2COOH-PEG-CH2COOMe

Alpha-(carboxymethyl)-omega-(methyl-protected carboxymethyl) poly(ethylene glycol) (HOOCCH2-PEG-CH2COOMe) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear carboxymethyl and methyl-ester-protected carboxymethyl groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The carboxymethyl group can be activated for coupling with primary amines. Its single methylene group defines the local connection between the reactive carboxyl group and the polyether chain. The methyl ester remains available for subsequent ester transformations, allowing a conjugatable carboxyl group to be introduced after other linking steps. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Carboxymethyl-PEG derivatization; Amide-linker synthesis; Local spacing studies at reactive termini; Carboxylic acid precursor synthesis; Sequential PEG derivatization; Ester-linker conversion. Customization available.

NHSOOCCH2-PEG-NHBoc

Alpha-(carboxymethyl N-hydroxysuccinimide ester)-omega-(tert-butoxycarbonyl-protected amino) poly(ethylene glycol) (NHSCOCH2-PEG-NHBoc) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear carboxymethyl NHS ester and Boc-protected amine groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The carboxymethyl NHS ester can directly couple to primary-amine-containing components, enabling comparisons of the short spacing between the activated site and the polyether chain. Boc protection separates amine reactions from other synthetic steps. Appropriate deprotection exposes a primary amine for subsequent conjugation. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Primary-amine labeling and conjugation; Carboxymethyl activated-ester linkers; Protein surface modification; Protected PEG linkers; Sequential bioconjugation synthesis; Primary-amine precursor construction. Customization available.

NHSOOCCH2-PEG-NHFmoc

Alpha-(carboxymethyl N-hydroxysuccinimide ester)-omega-(fluorenylmethoxycarbonyl-protected amino) poly(ethylene glycol) (NHSCOCH2-PEG-NHFmoc) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear carboxymethyl NHS ester and Fmoc-protected amine groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The carboxymethyl NHS ester can directly couple to primary-amine-containing components, enabling comparisons of the short spacing between the activated site and the polyether chain. Fmoc protection facilitates sequential conjugation. Amine coupling can follow deprotection under conditions compatible with the target system. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Primary-amine labeling and conjugation; Carboxymethyl activated-ester linkers; Protein surface modification; Orthogonal protection and linker synthesis; Peptide conjugation intermediates; Sequential amine functionalization. Customization available.

NHSOOCCH2-PEG-NHCbz

Alpha-(carboxymethyl N-hydroxysuccinimide ester)-omega-(benzyloxycarbonyl-protected amino) poly(ethylene glycol) (NHSCOCH2-PEG-NHCbz) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear carboxymethyl NHS ester and Cbz-protected amine groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The carboxymethyl NHS ester can directly couple to primary-amine-containing components, enabling comparisons of the short spacing between the activated site and the polyether chain. The Cbz-protected end retains a releasable amine precursor, allowing amine coupling and transformations at the other terminus to be performed sequentially. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Primary-amine labeling and conjugation; Carboxymethyl activated-ester linkers; Protein surface modification; Protected amino linkers; Sequential end-group transformations; Functional molecular module synthesis. Customization available.

NHSOOCCH2-PEG-CH2COONHS Ester

Alpha,omega-bis(carboxymethyl N-hydroxysuccinimide ester) poly(ethylene glycol) (NHSCOCH2-PEG-CH2CONHS) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear carboxymethyl NHS ester groups. Discrete chain lengths with different degrees of polymerization are available. The carboxymethyl NHS ester can directly couple to primary-amine-containing components, enabling comparisons of the short spacing between the activated site and the polyether chain. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Primary-amine labeling and conjugation; Carboxymethyl activated-ester linkers; Protein surface modification. Customization available.

NHSOOCCH2CH2-PEG-CH2CH2COONHS Ester

Alpha,omega-bis(carboxyethyl N-hydroxysuccinimide ester) poly(ethylene glycol) (NHSCOCH2CH2-PEG-CH2CH2CONHS) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear carboxyethyl NHS ester groups. Discrete chain lengths with different degrees of polymerization are available. The carboxyethyl NHS ester can couple to primary amines while retaining an extended local spacer for designing different conjugation distances. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Primary-amine-reactive linkers; Extended activated-ester synthesis; Spacer-structure comparisons. Customization available.

BocNH-PEG-NHBoc

Alpha,omega-bis(tert-butoxycarbonyl-protected amino) poly(ethylene glycol) (BocNH-PEG-NHBoc) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear Boc-protected amine groups. Discrete chain lengths with different degrees of polymerization are available. Boc protection separates amine reactions from other synthetic steps. Appropriate deprotection exposes a primary amine for subsequent conjugation. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Protected PEG linkers; Sequential bioconjugation synthesis; Primary-amine precursor construction. Customization available.

FmocNH-PEG-NHFmoc

Alpha,omega-bis(fluorenylmethoxycarbonyl-protected amino) poly(ethylene glycol) (FmocNH-PEG-NHFmoc) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear Fmoc-protected amine groups. Discrete chain lengths with different degrees of polymerization are available. Fmoc protection facilitates sequential conjugation. Amine coupling can follow deprotection under conditions compatible with the target system. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Orthogonal protection and linker synthesis; Peptide conjugation intermediates; Sequential amine functionalization. Customization available.

CbzNH-PEG-NHCbz

Alpha,omega-bis(benzyloxycarbonyl-protected amino) poly(ethylene glycol) (CbzNH-PEG-NHCbz) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear Cbz-protected amine groups. Discrete chain lengths with different degrees of polymerization are available. The Cbz-protected end retains a releasable amine precursor, allowing amine coupling and transformations at the other terminus to be performed sequentially. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Protected amino linkers; Sequential end-group transformations; Functional molecular module synthesis. Customization available.

BocNH-PEG-NHFmoc

Alpha-(tert-butoxycarbonyl-protected amino)-omega-(fluorenylmethoxycarbonyl-protected amino) poly(ethylene glycol) (BocNH-PEG-NHFmoc) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear Boc-protected amine and Fmoc-protected amine groups, respectively. Discrete chain lengths with different degrees of polymerization are available. Boc protection separates amine reactions from other synthetic steps. Appropriate deprotection exposes a primary amine for subsequent conjugation. Fmoc protection facilitates sequential conjugation. Amine coupling can follow deprotection under conditions compatible with the target system. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Protected PEG linkers; Sequential bioconjugation synthesis; Primary-amine precursor construction; Orthogonal protection and linker synthesis; Peptide conjugation intermediates; Sequential amine functionalization. Customization available.

BocNH-PEG-NHCbz

Alpha-(tert-butoxycarbonyl-protected amino)-omega-(benzyloxycarbonyl-protected amino) poly(ethylene glycol) (BocNH-PEG-NHCbz) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear Boc-protected amine and Cbz-protected amine groups, respectively. Discrete chain lengths with different degrees of polymerization are available. Boc protection separates amine reactions from other synthetic steps. Appropriate deprotection exposes a primary amine for subsequent conjugation. The Cbz-protected end retains a releasable amine precursor, allowing amine coupling and transformations at the other terminus to be performed sequentially. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Protected PEG linkers; Sequential bioconjugation synthesis; Primary-amine precursor construction; Protected amino linkers; Sequential end-group transformations; Functional molecular module synthesis. Customization available.

FmocNH-PEG-NHCbz

Alpha-(fluorenylmethoxycarbonyl-protected amino)-omega-(benzyloxycarbonyl-protected amino) poly(ethylene glycol) (FmocNH-PEG-NHCbz) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear Fmoc-protected amine and Cbz-protected amine groups, respectively. Discrete chain lengths with different degrees of polymerization are available. Fmoc protection facilitates sequential conjugation. Amine coupling can follow deprotection under conditions compatible with the target system. The Cbz-protected end retains a releasable amine precursor, allowing amine coupling and transformations at the other terminus to be performed sequentially. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Orthogonal protection and linker synthesis; Peptide conjugation intermediates; Sequential amine functionalization; Protected amino linkers; Sequential end-group transformations; Functional molecular module synthesis. Customization available.

BocNH-PEG-ONH2

Alpha-(tert-butoxycarbonyl-protected amino)-omega-(aminooxy) poly(ethylene glycol) (BocNH-PEG-ONH2) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear Boc-protected amine and aminooxy groups, respectively. Discrete chain lengths with different degrees of polymerization are available. Boc protection separates amine reactions from other synthetic steps. Appropriate deprotection exposes a primary amine for subsequent conjugation. The aminooxy group can condense with aldehydes or ketones to form oxime bonds, providing a conjugation route for carbonyl-containing molecules and carriers. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Protected PEG linkers; Sequential bioconjugation synthesis; Primary-amine precursor construction; Oxime ligation; Carbonyl-site labeling; Glycan and functional-probe conjugation. Customization available.

FmocNH-PEG-ONH2

Alpha-(fluorenylmethoxycarbonyl-protected amino)-omega-(aminooxy) poly(ethylene glycol) (FmocNH-PEG-ONH2) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear Fmoc-protected amine and aminooxy groups, respectively. Discrete chain lengths with different degrees of polymerization are available. Fmoc protection facilitates sequential conjugation. Amine coupling can follow deprotection under conditions compatible with the target system. The aminooxy group can condense with aldehydes or ketones to form oxime bonds, providing a conjugation route for carbonyl-containing molecules and carriers. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Orthogonal protection and linker synthesis; Peptide conjugation intermediates; Sequential amine functionalization; Oxime ligation; Carbonyl-site labeling; Glycan and functional-probe conjugation. Customization available.

CH2COOtBu-PEG-CH2COOtBu

Alpha,omega-bis(tert-butyl-protected carboxymethyl) poly(ethylene glycol) (tBuOOCCH2-PEG-CH2COOtBu) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear tert-butyl-ester-protected carboxymethyl groups. Discrete chain lengths with different degrees of polymerization are available. The tert-butyl ester temporarily protects a carboxyl precursor. Appropriate acidic deprotection enables subsequent carboxyl activation and amide coupling. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Protected carboxylic acid linkers; Sequential end-group conjugation; PEG synthetic intermediates. Customization available.

CH2COOMe-PEG-CH2COOMe

Alpha,omega-bis(methyl-protected carboxymethyl) poly(ethylene glycol) (MeOOCCH2-PEG-CH2COOMe) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear methyl-ester-protected carboxymethyl groups. Discrete chain lengths with different degrees of polymerization are available. The methyl ester remains available for subsequent ester transformations, allowing a conjugatable carboxyl group to be introduced after other linking steps. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Carboxylic acid precursor synthesis; Sequential PEG derivatization; Ester-linker conversion. Customization available.

OTs-PEG-OTs

Alpha,omega-bis(p-toluenesulfonate) poly(ethylene glycol) (TsO-PEG-OTs) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear tosylate groups. Discrete chain lengths with different degrees of polymerization are available. The tosylate acts as a leaving group, enabling nitrogen- or sulfur-containing functional moieties to be introduced by nucleophilic substitution. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: PEG end-group conversion; Nucleophilic substitution intermediates; Linker extension. Customization available.

OMs-PEG-OMs

Alpha,omega-bis(methanesulfonate) poly(ethylene glycol) (MsO-PEG-OMs) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear mesylate groups. Discrete chain lengths with different degrees of polymerization are available. The mesylate provides a handle for nucleophilic substitution, allowing chain-segment construction and installation of the final functional terminus to be performed separately. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: End-group nucleophilic substitution; Functional PEG synthesis; Chain-extension intermediates. Customization available.

Cl-PEG-Cl

Alpha,omega-bis(chloro) poly(ethylene glycol) (Cl-PEG-Cl) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear chloro group groups. Discrete chain lengths with different degrees of polymerization are available. The chloro terminus can serve as a precursor for suitable nucleophilic substitution reactions to introduce target functional moieties. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Halogenated PEG derivatization; Nucleophilic substitution intermediates; Chain-segment conjugation studies. Customization available.

Br-PEG-Br

Alpha,omega-bis(bromo) poly(ethylene glycol) (Br-PEG-Br) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear bromo group groups. Discrete chain lengths with different degrees of polymerization are available. The bromo terminus retains a handle for subsequent nucleophilic substitution, facilitating the introduction of nitrogen- or sulfur-containing linking moieties. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Bromo end-group conversion; Linker synthesis; Installation of functional moieties. Customization available.

I-PEG-I

Alpha,omega-bis(iodo) poly(ethylene glycol) (I-PEG-I) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear iodo group groups. Discrete chain lengths with different degrees of polymerization are available. The iodo terminus can be used in suitable nucleophilic substitution routes, enabling comparisons of different halogenated linker precursors and their derivatives. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Iodo-PEG intermediates; Terminal substitution reactions; Functional-molecule synthesis. Customization available.

OAc-PEG-OAc

Alpha,omega-bis(acetoxy) poly(ethylene glycol) (AcO-PEG-OAc) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear acetoxy groups. Discrete chain lengths with different degrees of polymerization are available. The acetate temporarily masks the hydroxyl group. Appropriate deprotection restores the opportunity for further hydroxyl derivatization. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Hydroxyl protection and deprotection; Sequential PEG derivatization; Acetate-linkage structure studies. Customization available.

Acrylate-PEG-Acrylate

Discrete poly(ethylene glycol) diacrylate (Acrylate-PEG-Acrylate) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear acrylate groups. Discrete chain lengths with different degrees of polymerization are available. The acrylate double bond can participate in radical polymerization or suitable thiol addition reactions to introduce a polymerizable PEG segment. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Polymerizable PEG monomers; Thiol-addition conjugation; Hydrogel and crosslinked-network studies. Customization available.

Methacrylate-PEG-Methacrylate

Discrete poly(ethylene glycol) dimethacrylate (Methacrylate-PEG-Methacrylate) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear methacrylate groups. Discrete chain lengths with different degrees of polymerization are available. The methacrylate can undergo radical polymerization or copolymerization, covalently incorporating the PEG segment into polymer materials. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Functional PEG monomers; Hydrophilic copolymer materials; Crosslinked networks and surface grafting. Customization available.

VinylEther-PEG-VinylEther

Alpha,omega-bis(vinyl ether) poly(ethylene glycol) (VinylEther-PEG-VinylEther) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear vinyl ether groups. Discrete chain lengths with different degrees of polymerization are available. The vinyl ether retains a double bond available for polymerization or addition in compatible chain-segment polymerization and functionalization routes. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Vinyl ether polymerization; Reactive hydrophilic segments; Functional-material synthesis. Customization available.

Allyl-PEG-Allyl

Discrete poly(ethylene glycol) diallyl ether (Allyl-PEG-Allyl) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear allyl ether groups. Discrete chain lengths with different degrees of polymerization are available. The allyl group can participate in thiol–ene reactions or suitable alkene transformations, providing a conjugation handle for thiol-containing modules. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Thiol–ene conjugation; Alkenyl-functional PEG; Crosslinked materials and surface modification. Customization available.

Glycidyl-PEG-Glycidyl

Discrete poly(ethylene glycol) diglycidyl ether (Glycidyl-PEG-Glycidyl) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear glycidyl ether groups. Discrete chain lengths with different degrees of polymerization are available. The epoxide can undergo ring-opening addition with suitable nucleophiles, such as amines or thiols, for subsequent segment linking and material crosslinking. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Epoxide ring-opening conjugation; Amine- and thiol-containing material conjugation; Functional polyether synthesis. Customization available.

CH2CONHH2N-PEG-CH2CONHNH2

Alpha,omega-bis(carboxymethyl hydrazide) poly(ethylene glycol) (H2NNHCOCH2-PEG-CH2CONHNH2) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear carboxymethyl hydrazide groups. Discrete chain lengths with different degrees of polymerization are available. The hydrazide can condense with aldehydes or ketones to form hydrazone bonds. The carboxymethyl moiety retains a short spacer to the polyether chain. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Carbonyl capture; Hydrazone-linker synthesis; Acid-responsive linkage model studies. Customization available.

OH2N-PEG-ONH2

Alpha,omega-bis(aminooxy) poly(ethylene glycol) (H2NO-PEG-ONH2) is a homobifunctional precision PEG derivative with a defined chain length. Both ends bear aminooxy groups. Discrete chain lengths with different degrees of polymerization are available. The aminooxy group can condense with aldehydes or ketones to form oxime bonds, providing a conjugation route for carbonyl-containing molecules and carriers. Identical reactive sites at both ends support molecular bridging or derivatization on both sides. The conjugation scheme can be designed around the number of target sites. Applications: Oxime ligation; Carbonyl-site labeling; Glycan and functional-probe conjugation. Customization available.

HO-PEG-CH2CONHNH2

Alpha-(hydroxy)-omega-(carboxymethyl hydrazide) poly(ethylene glycol) (HO-PEG-CH2CONHNH2) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and carboxymethyl hydrazide groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. The hydrazide can condense with aldehydes or ketones to form hydrazone bonds. The carboxymethyl moiety retains a short spacer to the polyether chain. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Carbonyl capture; Hydrazone-linker synthesis; Acid-responsive linkage model studies. Customization available.

HO-PEG-NHBoc

Alpha-(hydroxy)-omega-(tert-butoxycarbonyl-protected amino) poly(ethylene glycol) (HO-PEG-BocNH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear hydroxyl and Boc-protected amine groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The terminal hydroxyl group can be further modified by esterification, etherification, or other functional-group transformations. Boc protection separates amine reactions from other synthetic steps. Appropriate deprotection exposes a primary amine for subsequent conjugation. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Precision PEG derivatization; Bioconjugation linker synthesis; Drug modification and functional-molecule conjugation; Protected PEG linkers; Sequential bioconjugation synthesis; Primary-amine precursor construction. Customization available.

H2N-PEG-CH2CH2COOH

Alpha-(amino)-omega-(carboxy) poly(ethylene glycol) (H2N-PEG-COOH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear primary amine and carboxyl groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The primary amine can react with activated carboxyl groups or NHS esters to form amide bonds and introduce carboxyl-containing functional moieties. The carboxyl group can be activated for amide coupling with primary-amine-containing molecules, retaining a handle for subsequent ligand or carrier attachment. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Amide-based bioconjugation; Peptide and functional small-molecule conjugation; Amino-PEG derivatization; Amine-containing molecule conjugation; Drug and ligand modification; Carboxyl linker synthesis. Customization available.

Mal-PEG-CH2CH2COOH

Alpha-(maleimide)-omega-(carboxy) poly(ethylene glycol) (MAL-PEG-COOH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear maleimide and carboxyl groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The maleimide can add to cysteine thiols or other thiolated modules, providing a handle for conjugation at thiol sites. The carboxyl group can be activated for amide coupling with primary-amine-containing molecules, retaining a handle for subsequent ligand or carrier attachment. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Cysteine-site modification; Thiol-selective bioconjugation; Protein–functional material conjugation; Amine-containing molecule conjugation; Drug and ligand modification; Carboxyl linker synthesis. Customization available.

Mal(N-linked)-PEG-CH2CH2COONHS Ester

Alpha-(maleimide)-omega-(N-hydroxysuccinimide ester) poly(ethylene glycol) (MAL-PEG-NHS) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear maleimide and N-hydroxysuccinimide ester groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The maleimide can add to cysteine thiols or other thiolated modules, providing a handle for conjugation at thiol sites. The NHS ester can form amide bonds with primary amines, enabling conjugation to amine-containing small molecules, peptides, proteins, or material surfaces. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Cysteine-site modification; Thiol-selective bioconjugation; Protein–functional material conjugation; Amine modification in proteins and peptides; Amine-functionalized surface conjugation; Activated-ester linker synthesis. Customization available.

FmocNH-PEG-CH2COOH

Alpha-(fluorenylmethoxycarbonyl-protected amino)-omega-(carboxy) poly(ethylene glycol) (FmocNH-PEG-COOH) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear Fmoc-protected amine and carboxyl groups, respectively. Discrete chain lengths with different degrees of polymerization are available. Fmoc protection facilitates sequential conjugation. Amine coupling can follow deprotection under conditions compatible with the target system. The carboxyl group can be activated for amide coupling with primary-amine-containing molecules, retaining a handle for subsequent ligand or carrier attachment. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis. Applications: Orthogonal protection and linker synthesis; Peptide conjugation intermediates; Sequential amine functionalization; Amine-containing molecule conjugation; Drug and ligand modification; Carboxyl linker synthesis. Customization available.

PhthN-PEG-CH2CH2COOH

Phthalimido-poly(ethylene glycol)-propionic acid (PhthN-PEG-CH2CH2COOH) is a family of heterobifunctional precision PEG derivatives with defined chain lengths. One end is a phthalimide-protected structure linked through nitrogen to the carbon chain at the PEG terminus. The other is a propionic acid terminus of the form PEG-O-CH2-CH2-COOH. The carboxyl group can first be activated to form an amide with a primary-amine-containing molecule. The protected amine end retains a reaction site for subsequent sequential conjugation. Removal of the phthaloyl group under appropriate conditions yields the corresponding amino-PEG-propionic acid derivative. This series distinguishes discrete chain lengths by degree of polymerization, enabling comparisons of PEG spacer length in molecular conjugation and derivatization. Applications: Amino–carboxyl precision PEG intermediate synthesis; Sequential bioconjugation; ADC and PROTAC linker construction; Peptide and functional-molecule spacer design. Customization available.

HO-PEG-CH2COONa

HO-PEG-CH2CH2COOtBu

HO-PEG-CH2CH2COOBenzyl Ester

H2N-PEG-CH2CH2COOtBu

HS-PEG-N3

HS-PEG-Propyne

HS-PEG-CH2CH2COOtBu

HS-PEG-NH2·HCl

Mal-NH-PEG-CH2CH2COOH

Mal-NH-PEG-NH-Mal

Mal-NH-PEG-CH2CH2COOPFP Ester

Mal-PEG-Mal

Mal-PEG-CH2CH2COONHS Ester

N3-PEG-CH2COOH

N3-PEG-CH2CH2COOtBu

N3-PEG-Br

Propyne-PEG-Propyne

DBCO-NH-PEG-Biotin

DBCO-NH-PEG-Mal

Biotin-PEG-OH

Biotin-PEG-NH2

Biotin-PEG-CH2COOH

Biotin-PEG-CH2CH2COOH

Biotin-PEG-SH

Biotin-PEG-CH2COONHS Ester

Biotin-PEG-CH2CH2COONHS Ester

Biotin-PEG-SC

Biotin-PEG-Mal

Biotin-PEG-NH-Mal

Biotin-PEG-N3

Biotin-PEG-Propargyl

Biotin-PEG-DBCO

Biotin-PEG-BCN

Biotin-PEG-TCO

Biotin-PEG-ONH2

Biotin-PEG-Hydrazide

Biotin-PEG-CH2CONHNH2

Biotin-PEG-NHBoc

Biotin-PEG-NHFmoc

Biotin-PEG-NHCbz

Biotin-PEG-CH2COOtBu

Biotin-PEG-CH2COOMe

Biotin-PEG-Acrylate

Biotin-PEG-Methacrylate

Biotin-PEG-VinylEther

Biotin-PEG-Allyl

Biotin-PEG-Glycidyl

Biotin-PEG-OMs

Biotin-PEG-OTs

Biotin-PEG-Cl

Biotin-PEG-Br

Biotin-PEG-I

Biotin-PEG-OAc

Biotin-PEG-OPNP

Biotin-PEG-OSuc

Biotin-PEG-NHMe

Biotin-PEG-NMe2

Biotin-PEG-Biotin

Biotin-PEG-Folate

Biotin-PEG-SPDP

Methyltetrazine-CH2NHCO-PEG-OH

Methyltetrazine-CH2NHCO-PEG-NH2

Methyltetrazine-CH2NHCO-PEG-CH2COOH

Methyltetrazine-CH2NHCO-PEG-CH2CH2COOH

Methyltetrazine-CH2NHCO-PEG-SH

Methyltetrazine-CH2NHCO-PEG-CH2COONHS Ester

Methyltetrazine-CH2NHCO-PEG-CH2CH2COONHS Ester

Methyltetrazine-CH2NHCO-PEG-SC

Methyltetrazine-CH2NHCO-PEG-Mal

Methyltetrazine-CH2NHCO-PEG-CH2CH2NHMal

Methyltetrazine-CH2NHCO-PEG-N3

Methyltetrazine-CH2NHCO-PEG-CH2-C≡CH

Methyltetrazine-CH2NHCO-PEG-DBCO

Methyltetrazine-CH2NHCO-PEG-BCN

Methyltetrazine-CH2NHCO-PEG-TCO

Methyltetrazine-CH2NHCO-PEG-ONH2

Methyltetrazine-CH2NHCO-PEG-Hydrazide

Methyltetrazine-CH2NHCO-PEG-CH2CONHNH2

Methyltetrazine-CH2NHCO-PEG-NHBoc

Methyltetrazine-CH2NHCO-PEG-NHFmoc

Methyltetrazine-CH2NHCO-PEG-NHCbz

Methyltetrazine-CH2NHCO-PEG-CH2COOtBu

Methyltetrazine-CH2NHCO-PEG-CH2COOMe

Methyltetrazine-CH2NHCO-PEG-Acrylate

Methyltetrazine-CH2NHCO-PEG-Methacrylate

Methyltetrazine-CH2NHCO-PEG-VinylEther

Methyltetrazine-CH2NHCO-PEG-Allyl

Methyltetrazine-CH2NHCO-PEG-Glycidyl

Methyltetrazine-CH2NHCO-PEG-OMs

Methyltetrazine-CH2NHCO-PEG-OTs

Methyltetrazine-CH2NHCO-PEG-Cl

Methyltetrazine-CH2NHCO-PEG-Br

Methyltetrazine-CH2NHCO-PEG-I

Methyltetrazine-CH2NHCO-PEG-OAc

Methyltetrazine-CH2NHCO-PEG-OPNP

Methyltetrazine-CH2NHCO-PEG-OSuc

Methyltetrazine-CH2NHCO-PEG-NHMe

Methyltetrazine-CH2NHCO-PEG-NMe2

Methyltetrazine-CH2NHCO-PEG-Biotin

Methyltetrazine-CH2NHCO-PEG-Folate

Methyltetrazine-CH2NHCO-PEG-SPDP

BocNH-PEG-CH2COOH

BocNH-PEG-CH2CH2COOH

HS-(CH2)6-O-PEG-OCH3

H2N-PEG-NH-PEG-CH2COOH

Br-PEG-CH2COOH

BnO-PEG-OH

Hydrazide-PEG-Hydrazide

FmocNH-PEG-CH2CH2COOH