Optimized method for measuring aspartate aminotransferase activity with the CentrifiChem Analyzer, with automatic preincubation of serum.

We propose a routine method for the mechanized measurement of aspartate aminotransferase with the CentrifiChem Analyzer, which is based on the recommendations of both the International Federation of Clinical Chemistry and the Société Française de Biologie Clinique. A modification of the CentrifiChem pipettor permits simultaneous pipetting of two reagents, thus achieving automatic preincubation of the serum in the transfer disk. Owing to the fixed reagent volumes dispensed by the pipettor, preincubation conditions had to be modified, but the recommendations for the final reagent concentrations in the assay cuvet were observed. The totally automated method correlates very well with one involving manual pipetting to reproduce the detailed step-by-step recommendations of the International Federation of Clinical Chemistry. Intra-assay precision ranged from 3.4 to 4.9% and interassay precision from 1.7 to 7.5%. We assayed 135 sera and obtained a correlation coefficient of 0.996 (a = 1.025, b = 0.08).