Improved and effective assays of the glutamic oxaloacetic transaminase by the coenzyme-apoenzyme system (CAS) principle.

Standardized and reliable methods have been devised to assay preparations of the glutamic oxaloacetic transaminase from human erythrocytes by the CAS principle, i.e., the unsaturation and saturation of the coenzyme (pyridoxal 5'-phosphate) of a Coenzyme-Apoenzyme System. This dual enzymic assay is effective to detect and measure human deficiencies of vitamin B6. A preferred procedure has been developed, particularly for individuals and for limited groups, but is also applicable to large groups. A simplified procedure, which emphasizes the statistical significance of difference between large groups was also developed. Lyophilized erythrocyte hemolysates appear stable for up to 7 days for simplified transportation.