A SIMPLE BACTERIAL BIOASSAY FOR THE MEASUREMENT OF L-GLUTAMINE

The amino acid L-glutamine has been shown to be important to numerous cells in the body. However, the routine measurement of glutamine in bi ological solutions is complicated by its relative instability, particu larly at extremes of pH. We report a simple bacterial bioassay method for the estimation of glutamine, carried out at neutral pH, using an E scherichia coli that is specifically dependent on the presence of glut amine for replication. The assay is simple to perform and we have show n it to be highly reproducible. Furthermore, we observed significant c orrelation between the estimations of glutamine by the bioassay system and current methodologies. The levels of glutamine recorded were high er than by other methods. We also found that deproteinization and neut ralization of samples allowed them to be stored at -70 degrees C for u p to 24 weeks without deterioration.