Calibration of the Ektachem Amylase method using human reference materials and the Phadebas Blue Starch method as an interim reference method.
In a multilaboratory study a consensus was established to calibrate the Ektachem Amylase method to reproduce the results of the Phadebas Blue Starch method. The calibration graph has a slope = 3.39 and intercept = 25. For the Ektachem Amylase method the reaction-rate ratio between salivary and pancreatic amylase was calculated to be 0.89, relative to that of the Phadebas Blue Starch method. A calibration value for the Nordic Amylase Calibrator to be used on Ektachem analysers was determined to be close to 469 U l-1 for the current batch. However, since the difference from the stated value of 460 U l-1 is negligible, the authors recommend the use of the stated value for this and future batches of the Nordic Amylase Calibrator. An error of around 10% introduced by the presence of salivary amylase is comparable to the methods accepted by the Scandinavian Committee on Enzymes. Introduction of a consensus calibration reduced the interlaboratory variation by up to 40% at all levels.
Department of Clinical Chemistry, Herning Centralsygehus, Denmark.
P K
PK
Mogensen
J
J
Møller
L
L
Nyborg
E
E
Magid
N
N
Wimmelmann
A
A
Uldall
D000681:Amylases / Q000032:analysis*; D015415:Biomarkers / Q000032:analysis; D005069:Evaluation Studies as Topic; D006801:Humans; D010338:Pathology, Clinical / Q000379:methods*; D012015:Reference Standards; D012016:Reference Values
D015415:Biomarkers; D000681:Amylases