Description_x000D_ General description_x000D_ PharmaGrade products are manufactured under appropriate controls for use as a raw material in pharma or biopharmaceutical production. For more information on the PharmaGrade Program, visit sigma-aldrich.com/safc-pharmagrade._x000D_ To request the Enhanced Quality Product Documentation for this product, please contact Customer Support and select ‘Product Documentation’. Please note that access to the Enhanced Quality Product Documentation for this product requires a confidentiality disclosure agreement._x000D_ Application_x000D_ L-Isoleucine is an essential amino acid. It can be biosynthesized from threonine or through fermentation of carbohydrates. The amino acid L-isoleucine is an isomer of L-Leucine, differing in the position of the side chain. It is also considered to be a branched chain amino acid, along with L-Leucine and L-Valine, which are sources of fuel and/or transport during cell development. It is used as a cell culture media component in the commercial biomanufacture of therapeutic recombinant proteins and monoclonal antibodies.