title: Usefulness of reference materials in calibration of enzyme activities.
abstract: alpha-Amylase, alkaline phosphatase and gamma-glutamyltransferase were studied in a multicentre evaluation. Analyses were performed on different patient samples. Each enzyme was assayed in two different laboratories at both 30 and 37 degrees C, with widely used reagent kits and with the IFCC reference method (if in existence). Results differed considerably according to the measurement procedure. Data also showed that it was not possible to employ a constant conversion factor for one enzyme and different techniques between 30 and 37 degrees C. Calibration with three reference materials extensively improved the intermethod consistency for most of the tested measurement procedures. It was possible to transfer accuracy from the method used for the certification of the reference material to routine procedures, by using the reference material as calibrator. Temperature did not seem to be a crucial variable for the implement of the enzyme calibrator approach.
authors.affiliation: Laboratoire de Biochimie Appliquée et Laboratoire, Centre de Traumatologie et d'Orthopédie, Université Louis Pasteur de Strasbourg, Illkirch, France.
authors.forename: J M
authors.initials: JM
authors.lastname: Lessinger
authors.forename: G
authors.initials: G
authors.lastname: Férard
authors.forename: D
authors.initials: D
authors.lastname: Grafmeyer
authors.forename: D
authors.initials: D
authors.lastname: Labbé
authors.forename: I
authors.initials: I
authors.lastname: Maire
authors.forename: F
authors.initials: F
authors.lastname: Schiele
authors.forename: A
authors.initials: A
authors.lastname: Vassault
mesh_terms: D000469:Alkaline Phosphatase / Q000032:analysis* / Q000097:blood; D000818:Animals; D006801:Humans; D007753:Laboratories / Q000592:standards; D009206:Myocardium / Q000201:enzymology; D010179:Pancreas / Q000201:enzymology; D011786:Quality Control; D011933:Reagent Kits, Diagnostic; D012015:Reference Standards; D015203:Reproducibility of Results; D013552:Swine; D013696:Temperature; D000516:alpha-Amylases / Q000032:analysis* / Q000097:blood; D005723:gamma-Glutamyltransferase / Q000032:analysis* / Q000097:blood
chemical_list: D011933:Reagent Kits, Diagnostic; D005723:gamma-Glutamyltransferase; D000469:Alkaline Phosphatase; D000516:alpha-Amylases