A source of error in serum glutamicoxaloacetic transaminase determination.

In the summer of 1958 we observed that the results of serum glutamic-oxaloacetic transaminase (SGO T) determinations by the spectrophotometric method of Karmen, Wroblewski, and LaDue (1955) appeared to be appreciably higher than during previous months. This suspicion was confirmed when the sera from three out of six healthy young adults were found to give SGO-T values greater than 40 units per ml., the upper limit of the normal range found in these laboratories by Pryse-Davies and Wilkinson (1958). No increase during this period was noticed in the range of serum glutamic-pyruvic transaminase (SGP-T) figures determined by the similar method of Wr6blewski and LaDue (1956). The spectrophotometric SGO-T and SGP-T methods are based respectively on the following pairs of reactions: