Automated Determination of Serum Glutamic

A simplified and precise automated method is described for the colorimetric determi-nation of serum glutamic oxaloacetic transaminase. The enzymically generated oxaloacetic acid is dialyzed, coupled with Fast Ponceau L, a diazonium salt, to form a colored solution whose absorbance is measured at 455 m. Dialysis eliminates the need for a serum control determination, thereby halving the analysis time, which is usually 1 hr. per 40 specimens. Comparison of values obtained using this procedure with and without dialysis shows excellent agreement. Comparison with the spectro-photometric procedure shows good correlation. The results of sample interaction experiments are also presented. C ONSIDEItABLE EvIl)ENCE has now been accumulated concermliblg the diag-nostic value of serum glutamic oxaloacetic transaminase (SOOT) assays in myocardial infarction and other disease states (1). To cope with the consequent exponential increase in requests for this enzyme assay, several autormiated colorimetric procedures were introduced recently (2-4) for use on arm automated system (Technicon AutoAnalyzera). This paper presents an improved automated colorimetric procedure for tile determination of SOOT in this automated system. The i)rOCedure fea-tures dialysis of the enzymically generated oxaloacetate (for separatiomi from other diazo-reacting serum comlstituellts) and coupling under coii