Cysteine is a non-essential amino acid that can be synthesized by the human body under normal physiological conditions if a sufficient quantity of methionine is available. Cysteine is commonly used as a precursor in the food and pharmaceutical industries. Cysteine is used as a processing aid for baking, as an additive in cigarettes, as well as in the preparation of meat flavours.

DL-Cysteine, with its CAS registry number is 3374-22-9, is one kind of white solid. And its product categories are Pharmaceutical Intermediates; Amino Acids. It has slight bad smell and sour taste. In addition, this chemical is soluble in water, acetic acid, ammonia and ethanol, insoluble in ether, benzene, acetone, ethyl acetate, carbon disulfide and carbon tetrachloride.

Appearance and properties: white solid

Density: 1.334 g/cm</sup>3 </sup>

Boiling point: 293.9oC at 760 mmHg

Melting point: 225oC (dec.)

Flash point: 131.5oC

Refractive index: 1.549

Stable. Incompatible with strong oxidizing agents,

Storage conditions: Store in a tightly closed container. Store in a cool, dry,  well-ventilated area away from incompatible substances. Refrigerator (approx 4oC).