Description

L-Cysteine, S-(2-Aminoethyl)- (9Ci) is a modified amino acid derivative, specifically an S-alkylated cysteine, which introduces a reactive primary amine group via a thioether linkage. This unique bifunctional structure makes it a valuable intermediate for bioconjugation, peptide synthesis, and the development of biochemical probes. It is primarily sought by researchers and manufacturers in the pharmaceutical, biotechnology, and life science sectors for applications requiring site-specific modification or cross-linking.

Application

• Bioconjugation & Protein Labeling: Acts as a versatile linker for attaching fluorophores, drugs, or other molecules to proteins and peptides via its amine and thiol-reactive sites.
• Peptide Synthesis & Modification: Used as a building block in solid-phase peptide synthesis (SPPS) to introduce a functionalized side chain for further chemical elaboration.
• Cross-linking Agent: Serves as a heterobifunctional cross-linker for creating stable covalent bonds between biomolecules in structural biology and diagnostic assay development.
• Biochemical Probe Development: A key precursor for synthesizing activity-based probes and affinity tags used in chemoproteomics and enzyme studies.
• Pharmaceutical Intermediate: Employed in the research and development of novel therapeutic agents, including antibody-drug conjugates (ADCs).
• Material Science: Can be utilized for the surface functionalization of nanoparticles and other materials to impart biocompatibility or specific binding properties.

Basic Information

Product Name	L-Cysteine, S-(2-Aminoethyl)- (9Ci)
CAS No.	2936-69-8
Molecular Formula	C5H12N2O2S
Molecular Weight	164.22 g/mol
Synonyms	S-(2-Aminoethyl)-L-cysteine; L-S-(2-Aminoethyl)cysteine; 2-Amino-3-(2-aminoethylsulfanyl)propanoic acid; NSC 137783; (2R)-2-Amino-3-[(2-aminoethyl)sulfanyl]propanoic acid; AEC; S-Aminoethylcysteine
EINECS	220-920-3

Quality Control

Our L-Cysteine, S-(2-Aminoethyl)- is produced under strict quality management systems. Each batch undergoes comprehensive analytical testing, including chiral purity verification and impurity profiling, to ensure it meets the high standards required for research and development applications. A detailed Certificate of Analysis (COA) is provided with every shipment, confirming identity, purity, and other critical parameters.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at a controlled room temperature (15-25°C). This compound is hygroscopic (moisture-sensitive); therefore, the container must be kept tightly sealed in a dry environment to prevent degradation. For long-term storage, consider storing under an inert atmosphere.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥ 98.0%
Chiral Purity (HPLC)	≥ 99.0% L-isomer
Loss on Drying	≤ 1.0%
Residue on Ignition	≤ 0.1%
Heavy Metals	≤ 10 ppm

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