Figure 1. Controlled delivery of L-glutamine from media to cells in culture.
GlutaMAX vs. Glutamine
Get the most from your cell cultures with GlutaMAX-I
Gibco GlutaMAX-I is an improved cell culture supplement that can be used as a direct substitute for L-glutamine in your cell culture media.
L-glutamine is an essential nutrient in cell cultures for energy production as well as protein and nucleic acid synthesis. However, L-glutamine in cell culture media spontaneously degrades, generating ammonia and pyrrolidine carboxylic acid as byproducts.
GlutaMAX-I is a dipeptide, L-alanine-L-glutamine, which is more stable in aqueous solutions and does not spontaneously degrade. Gibco GlutaMAX media and media supplemented with the GlutaMAX-I supplement are suitable for both adherent and suspension mammalian cell cultures with little or no adaptation required.
The mechanism of dipeptide utilization involves the gradual release of peptidase during culture to allow the gradual hydrolysis of the dipeptide in the medium (Figure 1). This can be compared to the strategy of a fed-batch culture in which L-glutamine is continuously fed into the culture but maintained at low concentration. The result is an efficient energy metabolism and a high-growth yield.
How does GlutaMAX-I work?
When cells are cultured in media that contains GlutaMAX-I, the cells gradually release aminopeptidases which hydrolyze the dipeptide, slowly releasing L-alanine and L-glutamine into the culture media. The L-glutamine and L-alanine can then be taken up by the cells and utilized for protein production or in the TCA cycle. This can be compared to the fed-batch culture strategy in which L-glutamine is continuously fed into the culture but maintained at a low concentration. The result is an efficient energy metabolism and high growth yield without excess ammonia.
Figure 2. Human mesenchymal stem cells cultured with GlutaMAX media and stained with DAPI nuclear stain and primary CD105 antibody bound to a secondary Invitrogen Alexa Fluor 488 antibody.
Figure 3. Human mesenchymal stem cells cultured with GlutaMAX media under adipogenic differentiating conditions and stained with Hoechst 33342 nuclear stain, Invitrogen LipidTOX Green neutral lipid and Invitrogen MitoTracker Red.
How does GlutaMAX-I improve your cell culture?
Using GlutaMAX-I supplement in place of L-glutamine in cell culture can improve cell viability and growth, potentially increasing productivity levels.
Results may vary depending upon the cell line used. In an application-specific example, Figures 4 and 5 show an AE-1 cell growth curve and recombinant IgG1 production. The GlutaMAX-I culture demonstrates improved cell numbers and productivity.
GlutaMAX-I supplement can extend cell culture life, which may reduce the number of times the cells must be passaged and saves you time and money.
Figure 6 compares MDBK cells cultured in D-MEM with 10% FBS and L-glutamine or GlutaMAX-I supplement. Cells cultured in GlutaMAX-I reach peak density two days later and viability declines less rapidly than that observed in cultures with L-glutamine supplementation. The slight increase in lag phase is attributed to the time needed to release the peptidase and digest the dipeptide.
This allows a gradual increase in availability of L-glutamine to the cells.2
Figure 4. Cell growth. AE-1 mouse myeloma cells were seeded at 1x105 cells/mL. Samples were taken daily after three days and evaluated in triplicate for cell density. Cell viability was determined by trypan blue exclusion. Cell density continued to increase in samples containing GlutaMAX-I past the point when L-glutamine containing samples decreased in cell density.
Figure 5. IgG1 production. The samples from Figure 4 were also examined by ELISA for IgG1 production. GlutaMAX-I containing samples outperformed L-glutamine–containing samples.
Figure 6. MDBK cells were seeded at approximately 1x105 cells/flask in D-MEM with 10% FBS and L-glutamine or GlutaMAX-I in 25 cm2 T-flasks.
- Tritsch GL and Moore GE (1962) Spontaneous Decomposition of Glutamine in Cell Culture Media. Experimental Research 28:360–364.
- Hassell T, Gleave, S, and Butler, M (1991) Growth Inhibition in Cell Culture. Appl Biochem Biotechnol 30:30–41.
- Yang M, Butler, M (2002) Effects of Ammonia and Glucosamine on the Heterogeneity of Erythropoietin Glycoforms. Biotechnol Prog 18:129–138.
- Yang M, Butler, M (2000) Effects of Ammonia on the Glycosylation of Human Recombinant Erythropoietin in Culture. Biotechnol Prog 16:751–759.
- Christie A, Butler M (1994) Growth and Metabolism of a Murine Hybridoma in Cultures Containing Glutamine-based Dipeptides. FOCUS 16:1,9.
- Brand K, Feki W, et al. (1989) Metabolism 38:29.