In general, the advantages of McCoy’s 5A Medium-MAX over Regular McCoy’s 5A Medium are as follows:

  1. PH Capacity. The standard form of McCoy’s 5A -MAX contains 2.5 g/L of Sodium Bicarbonate. PurMa Biologics also manufactures McCoy’s 5A Medium with higher NaHCO3 (3.7 g/L) which provides higher protection against PH changes (Cat: P3M132724)
  1. Contains 2 mM L-Alanyl-L-Glutamine (0.434 g/L) instead of L-Glutamine and therefore:
  • Possess longer shelf life)
  • Minimizes toxic ammonia build-up.
  • Improves cell viability and growth.
  • Remains stable across a wide range of temperatures.
  • Minimizes the growth of pathogens by stabilizing the PH.
  • Improves the culture of primary cells.

Additionally, McCoy’s 5A-MAX contains:

  • 2 mM L-Alanyl-L-Glutamine (434 mg/L) (therefore possess longer shelf life)
  • Non-Essential Amino Acids
  • Sodium Bicarbonate (2.20 g/L)
  • Non-Essential Amino Acids
  • PurMa Biologics Manufactures several types of McCoy’s 5A Medium -MAX based on the amount of Sodium Bicarbonate and HEPES (PH capacity) requested.
  • Phenol Red
  • Moreover, High Glucose McCoy’s 5A Medium -MAX (4.5g /L) is available at PurMa Biologics (Cat: P3M129724)

L-glutamine is a vital amino acid that is supplemented with mammalian cell culture media. This important amino acid has several important functions including the production of purine and pyrimidine nucleotides amino sugars, and glutathione as well as performing as the secondary source of energy. The latter is more crucial in cells dividing rapidly.

One drawback of using L-glutamine is that in solutions such as cell culture media, L-glutamine degrades, resulting in the generation of toxic ammonia and pyrrolidine carboxylic acid. The speed of degradation of L-glutamine depends on time, temperature, and pH. One way to minimize the degradation of L-glutamine degradation in media is to gradually add these amino acids to your cell culture but has to be calculated to keep the level of L-glutamine at a constant level. Practically, this strategy even though is possible but tedious, and depending on the volume of cell culture work in your la, keeping track of time to keep the level of L-glutamine at the same level is difficult and could be tedious if not impossible.

A viable and well-proven alternative for using L-glutamine, which is less sensitive to environmental factors such as pH, is applying L-alanyl-L-glutamine, which is more stable in aqueous solutions and does not easily degrade and cells gradually release aminopeptidases that hydrolyze the dipeptide, slowly releasing L-alanine and L-glutamine into the culture media. The resulting L-glutamine and L-alanine are then used by the cells for protein production or in the TCA cycle. PurMaTM GluaSup (Cat# P3S210 559) is a proprietary combination of L-alanyl-L-glutamine and other elements which prevent degradation of L-glutamine in the period when is released from L-alanyl-L-glutamine before being utilized by cells. Using PurMaTM GluaSup maximizes energy metabolism and high growth yield. The other components in PurMaTM GluaSup neutralize the trace of ammonia on your cells whose generation in cell culture is inevitable in presence of L-glutamine and harmful to the cells.

Additionally, PurMaTM GluaSup offers more buffering capacity which maintains physiological pH more efficiently.  An extra buffering system in this media is a powerful tool to avoid changing the PH which results in instability in growing and cellular mechanisms. Changing the PH is also one of the most common factors for growing mold and other pathogens. McCoy’s 5A Medium -MAX functions better than regular McCoy’s 5A Medium on primary cell culture and most of the commercial cell lines such as MDCK, glial cells, fibroblasts, human endothelial cells, and rat fibroblasts. McCoy’s 5A Medium contains no proteins, lipids, or growth factors. Therefore, it requires supplementation, commonly with 10% Fetal Bovine Serum (FBS)

McCoy’s 5A Medium -MAX contains:

  • 2 mM L-Alanyl-L-Glutamine (434 mg/L) (therefore possess longer shelf life)
  • 2mM mM sodium pyruvate (220 mg/L)
  • Low glucose (1260 mg/L). For higher glucose please order P3M129108 McCoy’s 5A Medium
  • Non-Essential Amino Acids
  • Sodium Bicarbonate (2.5 g/L) for Lower NAHCO3 (1.5 g/L) order P3M157108; for Higher NAHCO3 (3.7 g/L), please order McCoy’s 5A Medium, Cat: P3M159108
  • Phenol Red
  • Lipoic Acid

The complete formulation can be found here: McCoy-MAX Formulation


  1. The survival of human skin stored by refrigeration at 4 degrees C in McCoy’s 5A medium: does oxygenation of the medium improve storage time? DeBono R, Rao GS, Berry RB.Plast Reconstr Surg. 1998 Jul;102(1):78-83. doi: 10.1097/00006534-199807000-00012.PMID: 9655410
  2. Mycoplasmal infection of insect cell cultures. Steiner T, McGarrity G.In Vitro. 1983 Sep;19(9):672-82. doi: 10.1007/BF02628958.PMID: 6413389
  3. Fresh and vitrified bovine preantral follicles have different nutritional requirements during in vitro culture. Castro SV, Carvalho AA, Silva CM, Santos FW, Campello CC, Figueiredo JR, Rodrigues AP.Cell Tissue Bank. 2014 Dec;15(4):591-601. doi: 10.1007/s10561-014-9432-2. Epub 2014 Mar 8.PMID: 24610241
  4. In vitro culture of postimplantation hamster embryos. Ebron-McCoy MT, Beyer PE, Oglesby LA, Kavlock RJ.Reprod Toxicol. 1988;2(1):31-6. doi: 10.1016/s0890-6238(88)80006-6.PMID: 2980399
  5. The turkey myogenic satellite cell: optimization of in vitro proliferation and differentiation. McFarland DC, Doumit ME, Minshall RD.Tissue Cell. 1988;20(6):899-908. doi: 10.1016/0040-8166(88)90031-6.PMID: 3245037
  6. Investigations on in vitro survival and virulence of T. pallidum under aerobiosis. Rathlev T. Br J Vener Dis. 1975 Oct;51(5):296-300. doi: 10.1136/sti.51.5.296. PMID: 172190
  7. Altered polyamine metabolism in Chinese hamster cells growing in a defined medium. Sertich GJ, Glass JR, Fuller DJ, Gerner EW.J Cell Physiol. 1986 Apr;127(1):114-20. doi: 10.1002/jcp.1041270115.PMID: 3958058
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  Sodium pyruvate
Indicator  Phenol red
Mycoplasma Detection Negative
Sterility Tested  Sterile filtered using 0.22 µm filter
Form Liquid
Shipping Condition  Room temperature