Use in mammalian cell culture as an alternative to pyridoxine or pyridoxal. Vitamin B6 is a required component of cell culture media. Historically, media have been supplemented with vitamin B6 in the aldehyde form, pyridoxal. While this is a biologically active form of vitamin B6, it is unstable in liquid media. When cells are able to utilize either pyridoxine and/or pyridoxamine, they are preferred supplement versus pyridoxal. A number of classical media are now offered with a choice between pyridoxal and pyridoxine as the vitamin A source.