Automated quantification of creatine kinase MB isoenzyme in serum by radial partition immunoassay, with use of the Stratus analyzer.
We evaluated the analytical and clinical performances of a new radial partition immunoassay for measuring the mass concentration of creatine kinase (CK)-MB in serum. All pipetting, washes, incubations and data reduction were performed in 8 min by the Stratus (Dade) fluorometric analyzer. Within-assay and between-assay CVs were respectively 5.5% and 8.4% at 21 micrograms/L, and 4.2% and 3.4% at 48 micrograms/L. Assaying serial dilutions of serum samples with high CK-MB concentrations demonstrated excellent linearity. Results of the Stratus technique correlated well (n = 115, r = 0.98) with those of the Tandem-E CKMB II assay. There was no interference from hemolysis, bilirubin, rheumatoid factor, or added CK-MM (up to 3500 U/L); consequently, CK-MB can be determined in undiluted serum, even in the presence of high total CK activity. The mean CK-MB concentration in 105 blood donors was 1.9 (SD 1.3) micrograms/L. For seven myocardial infarction patients who received prompt fibrinolytic therapy, the mean CK-MB concentration was 4.5 (SD 1.8) micrograms/L at admission, and maximum concentrations, 119 (SD 94) micrograms/L, were recorded 16 h later. CK-MB returned to concentrations less than 10 micrograms/L within 72 h.
Department of Clinical Chemistry, University of Liège, CHU-B35, Belgium.
J P
JP
Chapelle
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M
el Allaf
D000208:Acute Disease; D000328:Adult; D001322:Autoanalysis; D003402:Creatine Kinase / Q000097:blood*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D007527:Isoenzymes; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000201:enzymology; D012016:Reference Values
D007527:Isoenzymes; D003402:Creatine Kinase