Contains L-glutamine, ribonucleosides, and deoxyribonucleosides.
Minimum Essential Medium was developed when Basal Media Eagle was not sufficient to support Hela cells. It was discovered that with certain media supplements, BME could be made to grow a wider variety of cells. MEM incorporates these modifications, such as higher concentrations of amino acids into its formulation. Additional supplementation to MEM has broadened the applications for this medium. Alpha modification of the medium includes the addition of the non-essential amino acids, sodium pyruvate, lipoic acid, ascorbic acid, biotin and vitamin B12.
One useful application for alpha MEM is as a selection media. Dihydrofolate Reductase (DHFR) is an enzyme which is necessary for purine synthesis. In the absence of exogenous purines, this enzyme is required for growth. Alpha MEM minus does not contain the ribonucleosides or the deoxyribonucleosides, and will not support the growth of cells that do not contain the gene to produce DHFR.