Culture supplement extracted from rice bran for better serum-free culture

Introduction In mammalian cell culture, fetal bovine serum (FBS) and proteins including albumin (BSA) have been extensively added to culture media as growth factor. But mammalderived factors are potent source of various infections such as abnormal prion and viruses, and so alternative supplement is eagerly required. The alternative must be chemically defined or obtained from plant, as well as should be produced in commercial quantities and stably supplied. As an alternative supplement, we focused on rice bran extract (RBE), by-product of milling in the production of refined white rice, because rice bran contains abundant nutrients and proteins [1] as well as antioxidants [2] and because rice is cultivated plant, indicative of huge and stable supply.