MEM α (Minimum Essential Medium α) is widely used for mammalian cell culture as well as selection for transfected DHFR-negative cells. MEM α can be used with a variety of suspension and adherent mammalian cells, including keratinocytes, primary rat astrocytes, and human melanoma cells. We offer a variety of MEM α modifications for a range of cell culture applications. Find the right formulation using the media selector tool.
The complete formulation is available.

Using MEM α
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. Therefore, MEM α requires supplementation, commonly with 10% Fetal Bovine Serum (FBS). MEM α uses a sodium bicarbonate buffer system (2.2 g/L), and therefore requires a 5–10% CO₂ environment to maintain physiological pH.

cGMP manufacturing and quality system
MEM α is manufactured at a cGMP-compliant facility located in Grand Island, New York. The facility is registered with the FDA as a medical device manufacturer and is certified to ISO 13485 standards. For supply chain continuity, we offer an identical MEM α product made in our Scotland facility (22571-020). This facility is registered with the FDA as a medical device manufacturer and is certified to the ISO 13485 standard.