Abstract: The present invention provides a serum-free medium for culturing animal cells characterized in that it comprises 8.0-14.0 mg/l of methionine. Although a wide variety of animal cells can effectively be cultured by means of the serum-free medium according to the present invention, said serum-free medium produces an excellent growth effect for culturing animal epithelial cells in particular.

Abstract: The present invention provides the process for treating the animal hairs by solubilization wherein the animal hairs can be treated in a short time without any complicated operations and special apparatuses, and the process for recovering the solubilized product of the animal hairs wherein said product can be recovered simply and efficiently from the solution thereof. The former is the process for treating animal hairs by solubilization which comprises solubilizing the animal hairs in a weak alkaline liquid medium in the presence of an oxidizing agent whose concentration is high. The latter is the process for recovering a solubilized product of animal hairs which comprises admixing a solution of said product with an organic acid or an aqueous solution thereof to precipitate said product.

Abstract: The present invention relates to the production of descaled animal fiber. The scale is effectively removed by oxidation of a surface of the animal fiber with an oxidizing reagent, following by treatment with a proteolytic enzyme in the presence of salt. The resulting animal fiber has excellent shrink-proof properties.