Description

Thiol-Peg-Acid CAS NO 165729-81-7 is a heterobifunctional polyethylene glycol (PEG) derivative featuring a thiol group at one terminus and a carboxylic acid group at the other. This dual functionality is critical for creating stable, site-specific conjugations in aqueous and biological environments, bridging materials with different chemical properties. It is an essential building block for researchers and manufacturers in bioconjugation, drug delivery system development, surface functionalization, and advanced material science.

Application

• Bioconjugation and Linker Chemistry: Used to covalently attach peptides, proteins, antibodies, or other biomolecules to surfaces, nanoparticles, or other polymers via the thiol and carboxyl groups.
• PEGylation Reagent: Serves as a functional PEG spacer to improve solubility, reduce immunogenicity, and prolong circulation time of therapeutic agents like drugs and proteins.
• Surface Modification: Functionalizes gold surfaces (via thiol-gold chemistry) or other materials to create hydrophilic, non-fouling coatings for biosensors and diagnostic devices.
• Hydrogel Formation: Acts as a crosslinker in the synthesis of biocompatible hydrogels for tissue engineering and controlled drug release applications.
• Nanoparticle Functionalization: Modifies the surface of quantum dots, liposomes, and polymeric nanoparticles to enable targeted delivery and improve biocompatibility.
• Diagnostic Reagent Synthesis: Utilized in the preparation of labeled probes and contrast agents for imaging and diagnostic assays.

Basic Information

Product Name	Thiol-Peg-Acid
CAS No.	165729-81-7
Molecular Formula	C2n+4H4n+10On+3S (n=PEG repeat units)
Molecular Weight	Variable (depends on PEG chain length, e.g., 1kDa, 2kDa, 5kDa). Contact for details.
Synonyms	HS-PEG-COOH; α-Mercapto-ω-carboxy polyethylene glycol; Mercapto-PEG-Carboxylic Acid; Thiol-PEG-Carboxylic Acid; SH-PEG-COOH; PEG-dithiol-acid; Carboxy-PEG-Thiol; Poly(ethylene glycol) methyl ether 3-mercaptopropionate
EINECS	Contact for details.

Quality Control

Our Thiol-Peg-Acid is produced under strict quality management protocols. Each batch undergoes comprehensive analytical testing, including HPLC for purity and assay, NMR for structural confirmation, and titration for functional group quantification. We provide Certificates of Analysis (COA) with every shipment, detailing all relevant specifications to ensure traceability and compliance with your research or cGMP-grade requirements.

Storage

Preserve in a tightly closed container, protected from light. For long-term stability, store desiccated at -20°C under an inert atmosphere (argon or nitrogen) to prevent oxidation of the thiol group and moisture absorption. Allow the product to equilibrate to room temperature in a desiccator before opening to prevent condensation.

Specification

Item	Specification
Appearance	White to off-white waxy solid or viscous liquid
Identification (IR)	Conforms to structure
PEG Average Molecular Weight	As ordered (e.g., 1000, 2000, 5000 Da)
Assay (HPLC)	≥ 95%
Thiol Content (Titration)	≥ 90% of theoretical
Carboxylic Acid Content (Titration)	≥ 90% of theoretical
Water Content (KF)	≤ 1.0%
Solvents (Residual)	Meets ICH guidelines

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.