Day 39 : What is DMEM (Dulbecco's Modified Eagle Medium)?

In 1955, Basal Minimal Eagle (BME) medium was developed by Harry Eagle by adding ten essential amino acids as well as cystine, tyrosine, and glutamine to maintain the culture of HeLa cells and mouse fibroblasts. Besides that, it contains eight B vitamins.

Dulbecco's Modified Eagle's medium (DMEM) is a modified version of BME which has a four-fold higher concentration of amino acids and vitamins. It also contains salts, glucose and a pH indicator (phenol red) but no proteins or growth promoting agents. Some additional supplementary components such as Fetal Bovine Serum (FBS), L-Glutamine, sodium pyruvate, F12 or higher glucose level (4500 mg/L) are needed for optimal performance.

• Amino acids (arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine, cystine, tyrosine, and glutamine)
• Salts (calcium chloride, potassium chloride, magnesium sulfate, sodium chloride, and monosodium phosphate)
• Glucose (normally 1000 mg/L)
• Vitamins (folic acid, nicotinamide, riboflavin, B12)

An addition of sodium bicarbonate acts as a buffer system in the media. Powder media is formulated without sodium bicarbonate because it tends to gas off in the powdered state. 5 % CO2 works well to maintain the required pH in the range of 7.2-7.4. Exposure to ambient levels of CO2 causes DMEM to become basic rapidly.

Reference:
http://www.sigmaaldrich.com/life-science/cell-culture/classical-media-salts/dmem.html
http://tools.lifetechnologies.com/content/sfs/productnotes/F_DMEM%20-RD-MKT-TL-HL050602.pdf
http://www.bioind.com/page_14337