Hydrochloride salt of labelled L-Glutamine (G597000). L-Glutamine is an essential amino acid that is a crucial component of culture media that serves as a major energy source for cells in culture. L-Glutamine is very stable as a dry powder and as a frozen solution. In liquid media or stock solutions, however, L-glutamine degrades relatively rapidly. Optimal cell performance usually requires supplementation of the media with L-glutamine prior to use.