Trypsin is a kind of serine proteolytic enzyme, with molecular weight of 23300 dalton, and is a single peptide chain composed of 223 amino acid residues. With rigorous specificity, the trypsin specifically acts on the peptide linkage constituted by the basic amino acid arginine and leucine. Enzyme easily autolyzes by itself, and its activation also reduces or loses gradually. It is easily soluble in the water, but insoluble in trichloromethane, ethanol, ether and glycerin, and the optimum PH is 8.0~9.0. When the PH is 1.8, it is hardly deactivated when boiled for a short time; if the salt is added into the hot solution, the protein will precipitate, and the enzyme action of filtrate cannot be seen, and Ca2+ plays the role in protecting and activating the trypsin. Function It is used for the treatment of local edema, hematoma and abscess caused by empyema, hemothorax, surgical inflammation, ulcers, traumatic injuries and fistula, or spray inhalation for respiratory diseases, and also treatment for injury by poisonous snake. It is also often used for treating tissues before the culture of animal cells.