Four immunoassay methods and standards compared for measuring fibronectin.
Several companies have developed commercial kits to measure plasma fibronectin rapidly and inexpensively with readily available laboratory equipment. In two of these kits (Cooper Biomedical and Boehringer-Mannheim) an immunoturbidimetric method is used. In a third kit (Biomedical Technologies, Inc.) an enzyme immunoassay method is used. To evaluate these commercial kits for fibronectin assay, we selected nephelometry as a comparison method for ranking the kits with regard to precision and accuracy. We also compared antibody and fibronectin cross reactivity. The antibodies from various manufacturers appear similar, but the fibronectin standards from different sources showed significant variation. Rate nephelometry and the Boehringer-Mannheim kit had the best within-run precision (CVs of 0.38% and 5.5% respectively). Between-run precision for nephelometry was excellent (CV = 1.9%) and somewhat high for the Boehringer-Mannheim kit (CV = 15.4%). This study demonstrates a need for further standardization of antigen (fibronectin) and antibody in commercial kits and the development of suitable stable quality-control material.
D000906:Antibodies / Q000592:standards; D003429:Cross Reactions; D005353:Fibronectins / Q000097:blood* / Q000592:standards; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007124:Immunoenzyme Techniques; D009391:Nephelometry and Turbidimetry / Q000379:methods; D011786:Quality Control; D011933:Reagent Kits, Diagnostic / Q000592:standards*
D000906:Antibodies; D005353:Fibronectins; D011933:Reagent Kits, Diagnostic