Minimum Essential Medium (MEM) is a modification of Basal Medium Eagle (BME) that was developed by Harry Eagle to meet the specific nutritional requirements of certain subtypes. It includes higher concentrations of amino acids so the medium more closely approximates the protein composition of cultured mammalian cells. MEM has been used for the cultivation of a wide variety of cells grown in monolayers attached or in suspension cell lines, such as HeLa, BHK-21, 293, HEP-2, HT-1080, MCF-7, and fibroblasts as well as primary rat astrocytes. We offer MEM modifications for a range of cell culture applications. MEM is available with Earle’s salts for use in a CO2 incubator, or with Hanks’ salts for use without CO2. MEM contains no proteins, lipids, or growth factors. Therefore, MEM requires supplementation, commonly with 10% fetal bovine serum (FBS). MEM also uses a sodium bicarbonate buffer system (2.2 g/L) that requires a 5–10% CO2 environment to maintain physiological pH.

PurMaTM MEM media in Earls buffer includes earls’ buffer with the following formulation

  • As the composition of Earls buffer, it contains:
  1. Calcium chloride
  2. Magnesium sulfate
  3. Potassium chloride
  4. Sodium bicarbonate
  5. Sodium chloride
  6. Sodium Phosphate, monobasic
  • Low level of glucose (1.00 g/ liter)
  • Sodium bicarbonate (2.2 g/L) (if higher than 5% CO2 is used, a higher % of sodium bicarbonate is needed.
  • 2 mM L-glutamine (292 mg/L)’

PurMa Biologics manufactures 118 types of MEM that accommodate any form of this medium. We recommend contacting our friendly customer service & technical support about your exact need for MEM media.

Why PurMa Biologics? Why we stand behind our cell culture media:

  1. Our products are the outcome of 30 years of experience in cutting-edge cell and tissue culture science.
  2. We routinely manufacture over 1500 media which is the most comprehensive collection of cell and tissue culture media.
  3. We utilize %99 pure amino acids. This will significantly increase the consistency among your experiments, and the result of your lab compared to other laboratories working on the same issues.
  4. Considering the highest quality, our prices are extremely reasonable.

Formulation: for complete formulation click here: MEM in Earls Buffer Formulation


  1. Culture of granulosa cells in collagen gels: the influence of cell shape on steroidogenesis. Carnegie JA, Byard R, Dardick I, Tsang BK. Biol Reprod. 1988 May;38(4):881-90. doi: 10.1095/biolreprod38.4.881. PMID: 3401543
  2. Myelin formation in rat dorsal root ganglion cultured in a serum-free medium. Ninomiya T, Takahashi K. J Anat. 1987 Jun;152:209-13. PMID: 3654371
  3. Long-term organ culture of hamster cheek pouch mucosa. Mock D, Main JH. J Oral Pathol. 1976 Jul;5(4):237-40. doi: 10.1111/j.1600-0714.1976.tb01770.x. PMID: 820846
  4. An experimental model for ovarian tumor invasion of cultured mesothelial cell monolayer. Sawada M, Shii J, Akedo H, Tanizawa O. Lab Invest. 1994 Mar;70(3):333-8. PMID: 8145527
  5. Biocompatibility of trypan blue with human corneal cells. van Dooren BT, Beekhuis WH, Pels E. Arch Ophthalmol. 2004 May;122(5):736-42. doi: 10.1001/archopht.122.5.736. PMID: 15136322
  6. Induction of osteogenic protein-1 expression by interleukin-1beta in cultured rabbit articular chondrocytes. Yoshida S, Kubota Y, Toba T, Horiuchi S, Shimamura T. Tohoku J Exp Med. 2002 Jun;197(2):101-9. doi: 10.1620/tjem.197.101. PMID: 12233782
  7. Heat-stabilized albumin microspheres as a sustained drug delivery system for the antimetabolite, 5-fluorouracil. Truter EJ. Artif Cells Blood Substit Immobil Biotechnol. 1995;23(5):579-86. doi: 10.3109/10731199509117972. PMID: 8528451
  8. Roles of transforming growth factor beta in inhibition of androgen-induced growth of Shionogi carcinoma cells in serum-free medium. Yamanishi H, Nonomura N, Tanaka A, Yasui T, Nishizawa Y, Matsumoto K, Sato B. Cancer Res. 1990 Oct 1;50(19):6179-83. PMID: 2169337
  9. Leucine suppresses acid-induced protein wasting in L6 rat muscle cells. Bevington A, Brown J, Walls J. Eur J Clin Invest. 2001 Jun;31(6):497-503. doi: 10.1046/j.1365-2362.2001.00845.x. PMID: 11422399
  10. In vitro steroidogenesis by granulosa cells from equine pre-ovulatory follicles. Tucker KE, Henderson KA, Duby RT. J Reprod Fertil Suppl. 1991;44:45-55. PMID: 1795289
  11. Highly polarized secretion of inhibin by Sertoli cells in vitro. Handelsman DJ, Spaliviero JA, Kidston E, Robertson DM. 1989 Aug;125(2):721-9. doi: 10.1210/endo-125-2-721. PMID: 2546746
Parameter Specification
Appearance Red, clear liquid
pH 7.2 ± 0.1
Osmolality 275-360 mOsm/L
Endotoxin NMT< 2EU/mL
Mycoplasma Negative
Suitability  Suitable for mammalian cell culture
Additive N/A
Indicator Phenol red
Mycoplasma Detection Negative
Sterility Tested Sterile filtered using 0.22 µm filter
Form Liquid
Shipping Condition  Room temperature