Description_x000D_ General description_x000D_ Retinyl-acetate is a natural and ester derivative of vitamin A. It is found in classical media formulations such as M-199; NCTC-109 and William′s Medium E. Vitamin A is a component of serum useful in most serum containing cell culture systems._x000D_ Application_x000D_ Retinyl acetate has been used as a standard to measure the concentration of vitamin C in high performance liquid chromatography analysis (HPLC) and as a supplement in the preparation of the complete medium._x000D_ Packaging_x000D_ 1, 5 g in glass bottle_x000D_ Biochem/physiol Actions_x000D_ The oxidized form of retinol is retinoic acid, which has hormone-like growth factor and differentiation activity for epithelial and related cell types, especially neural cells. Retinoic acid induces embryonic stem cells to differentiate towards neural cells. Retinyl-acetate is known to be effective in treating breast cancer._x000D_ Other Notes_x000D_ All trans_x000D_ Preparation Note_x000D_ The melting point of this material is approx. 58 °C. In order to package, it was melted and may exist as a crystalline solid or as a supercooled viscous liquid.