Measurements of Serum L-Alanine Aminotransferase Activity on the CentrifiChem and on the LKB 8600

Abstract

A procedure for utilizing the CentrifiChem system for automated measurements of serum L-alanine aminotransferase (E.C. 2.6.1.2.) activity was designed. By incorporating a high LDH activity in the reagent, interference from the serum LDH-pyruvate reaction was reduced to a minimum. The problems around a lag-phase are discussed. Precision was increased by using two 4-minute measuring periods. Use of the simple CentrifiChem calculator necessitated increasing the NADH₂ concentration in the reagent to 250 μmol/I. With the described automated procedure, linearity exists in the range 5 U/1 to 230 U/l. With the described reagent and attachment of a small computer linearity can be extended to above 500 U/l. Intradisc precision was determined at two levels of L-alanine aminotransferase activity: Coefficients of variation with enzyme activities of 21 U/l and 139 U/l were 3 per cent and 1 per cent, respectively. Results on the CentrifiChem showed no significant difference from those obtained on the LKB 8600 with the method proposed by the Scandinavian Enzyme Committee. Throughput on the CentrifiChem is 120 to 150 samples per hour.

Key Words:

• Alanine aminotransferase
• CentrifiChem
• alanine aminotransferase
• serum
• centrifugal analyzer
• fast analyzer
• GPT
• CentrifiChem
• GPT
• serum