Traceability of values for catalytic activity concentration of enzymes: a Certified Reference Material for aspartate transaminase

Brigitte Toussaint, Hendrik Emons, Heinz G. Schimmel, Steffen Bossert-Reuther, Francesca Canalias, Ferruccio Ceriotti, Georges Férard, Carlo A. Ferrero, Paul F.H. Franck, F. Javier Gella, Joseph Henny, Poul J. Jørgensen (+6 others)
2010 Clinical Chemistry and Laboratory Medicine  
A new reference material for the liver enzyme aspartate transaminase (AST) (L-aspartate: 2-oxoglutarateaminotransferase, EC, also called aspartate aminotransferase (ASAT), has been developed under the code ERM-AD457/IFCC. This certified reference material (CRM) for AST has been produced from a human type recombinant AST expressed in Escherichia coli and a buffer containing bovine serum albumin, and has been lyophilised. Methods: The homogeneity and the stability of the material have
more » ... n tested and the catalytic activity concentration has been characterised by 12 laboratories using the reference procedure for AST at 378C from the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). Results: The certified catalytic activity concentration and certified uncertainty of AST in the reconstituted material are (1.74"0.05) mkat/L or (104.6"2.7) U/L (with a coverage factor ks2; 95% confidence interval). Conclusions: Both the certified value and uncertainty are traceable to the International System of Units (SI). The material is aiming to control the IFCC reference procedure for AST at 378C, which will then be used to assign values to calibrants and control materials. The present paper highlights the scientific challenges and innovations which were encountered during the development of this new CRM. Clin Chem Lab Med 2010;48:795-803.
doi:10.1515/cclm.2010.146 pmid:20441466 fatcat:k3gqsjdwhrewhep4ronncptsbe