Interlaboratory study of the IFCC method for alanine aminotransferase performed with use of a partly purified reference material

• Published in: Clinical chemistry (Baltimore, Md.) Vol. 38; no. 12; pp. 2365 - 2371
• Main Authors: Schiele, F, Muller, J, Colinet, E, Siest, G, Arzoglou, P, Brettschneider, H, Calam, DH, Ceriotti, F, Ferard, G, Frei, J
• Format: Journal Article
• Language: English
• Published: Washington, DC Am Assoc Clin Chem 01.12.1992; American Association for Clinical Chemistry
• Subjects: Alanine Transaminase - blood; Alanine Transaminase - metabolism; Alanine Transaminase - standards; Analytical, structural and metabolic biochemistry; Animals; Biological and medical sciences; Catalysis; Drug Contamination; Enzyme Stability; Enzymes and enzyme inhibitors; Freeze Drying; Fundamental and applied biological sciences. Psychology; Humans; Laboratories - standards; Myocardium - enzymology; Quality Control; Reagent Kits, Diagnostic - standards; Reference Standards; Spectrophotometry - standards; Substrate Specificity; Swine; Transferases; Characterization; Laboratory study; Alanine aminotransferase; Clinical chemistry; Enzyme
• ISSN: 0009-9147; 1530-8561
• DOI: 10.1093/clinchem/38.12.2365

We present the results of a study on performance of a reference material for alanine aminotransferase (ALT, EC 2.6.1.2) and the corresponding IFCC-approved method in an interlaboratory trial involving 13 laboratories. The ALT material was partly purified from pig heart (specific activity, 150 kU/g) and was essentially free of six potentially contaminating enzyme activities, including aspartate aminotransferase (EC 2.6.1.1). The partly purified ALT was lyophilized in a triethanolamine-buffered matrix, pH 6.4, containing bovine serum albumin and saccharose. Under these conditions, the predicted yearly loss of activity was 0.02% at 4 degrees C and < 0.01% at -20 degrees C. The final blank-corrected results of the accepted set of data gave a mean (SD) of 128.5 (5.1) U/L. The among-laboratory SD was 4.6 U/L and the within-laboratory SD was 2.0 U/L. The certified ALT catalytic concentration in the reconstituted material was 129 U/L with a 0.95 confidence interval of +/- 4 U/L.