Powdered MEM α Medium (Minimum Essential Medium α)

MEM α can be used with a variety of suspension and adherent mammalian cells, including keratinocytes, primary rat astrocytes, and human melanoma cells. MEM α is also available in a nucleoside-free version and can be used as a selection medium for DG44 and other DHFR negative cells. This product is made with Earle’s Balanced Salts. MEM alpha contains no proteins, lipids or growth factors. Therefore, MEM α requires supplementation, usually 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. For a wide range of cell culture applications, we offer modified MEM α media in a variety of compositions, as well as MEM α media with custom compositions.

Ingredients of Powdered MEM α Medium

This MEM α dry powder cell culture medium is formulated with sodium bicarbonate supplementation, pH adjustment and filtration. The detailed preparation scheme is as follows:

1. Add 950 mL of distilled water to a mixing vessel as close to final volume as possible.
2. Add dry medium to room temperature (15°C to 30°C) water and stir gently. Do not heat water.
3. Rinse the inside of the pack to remove any residual powder.
4. Add 29.3 mL of 75 g/L NaHCO3 solution to the medium.
5. Adjust the pH to 0.2 to 0.3 units below the desired final working pH by slowly adding and stirring 1 N NaOH or 1 N HCl. The pH may rise by 0.1 to 0.3 units after filtration. The recommended working pH is 7.1-7.4.
6. Adjust final volume with distilled water.
7. Immediately process the medium through the membrane filtration function of a 0.2 μm filter into a sterile container using a positive pressure system.