MEM α is a modification of Minimum Essential Medium (MEM) that contains non-essential amino acids, sodium pyruvate, lipoic acid, vitamin B12, biotin, and ascorbic acid. MEM α is available without nucleosides for use as a selection medium for DG44 and other DHFR-negative cells. This product is made with earle’s salts. MEM α contains no proteins, lipids, or growth factors