Gelatin, Skin Antibody from MyBioSource.com

Gelatin is a heterogeneous mixture of water-soluble proteins of high average molecular weights, present in collagen. The proteins are extracted by boiling skin, tendons, ligaments, bones, etc. in water. Type A gelatin is derived from acid-cured tissue and Type B gelatin is derived from lime-cured tissue. The charge on a gelatin molecule and its isoelectric point are primarily due to the carboxyl amino and guanidino groups on the side chains. Type A gelatin has 78-80 millimoles of free carboxyl groups per 100g of protein and a pI of 7.0-9.0; type B has 100-115 millimoles of free carboxyl groups per 100g of protein and a pI of 4.7-5.2. The pH of a 1.5% solution at 25 degree C is 3.8-5.5 for Type A and 5.0-7.5 for Type B. It is soluble in glycerol and acetic acid, and more soluble in hot than in cold water. It is practically insoluble in most organic solvents such as alcohol, chloroform, carbon disulfide, carbon tetrachloride, ether, benzene, acetone, and oils