title: Protein C in human plasma determined by homogeneous enzyme immunoassay with use of a centrifugal analyzer.
abstract: We describe the simple and rapid enzyme immunoassay of protein C in human plasma with use of a Cobas Fara centrifugal analyzer. The antibody, labeled with horseradish peroxidase, is reacted with antigen (protein C) for 15 min. The peroxidase activity of the resulting antigen-antibody conjugate is measured at 500 nm for 5 min in the presence of excess H2O2, phenol, and 4-aminoantipyrine, as compared with that of free conjugates. Results are calculated from a stored standard curve and expressed as a percentage of the value determined for a pooled specimen of normal adult plasma. The standard curve is linear from 0% to 200%. The CV is generally less than 4% for different concentrations of protein C. In liver cirrhosis, hepatocellular carcinoma, therapy with warfarin, thrombosis, and disseminated intravascular coagulation, protein C concentrations are about 40-70% of normal. Results obtained with the present homogeneous enzyme immunoassay correlated well with those by enzyme-labeled immunosorbent assay (r = 0.97).
mesh_terms: D000328:Adult; D001798:Blood Proteins / Q000032:analysis; D004211:Disseminated Intravascular Coagulation / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D006735:Horseradish Peroxidase; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007124:Immunoenzyme Techniques; D008107:Liver Diseases / Q000097:blood; D011486:Protein C / Q000097:blood*; D012016:Reference Values; D013927:Thrombosis / Q000097:blood; D014859:Warfarin / Q000009:adverse effects / Q000627:therapeutic use
chemical_list: D001798:Blood Proteins; D011486:Protein C; D014859:Warfarin; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase