Turbidimetric immunoassay of serum C-reactive protein
Otsuji, S.; Shibata, H.; Umeda, M.
Clinical Chemistry 28(10): 2121-2124
1982
ISSN/ISBN: 0009-9147 PMID: 6812987 Document Number: 189770
This rapid, reliable equilibrium turbidimetric immunoassay for serum C-reactive protein involves a potent monospecific antibody. Polyethylene glycol-6000 to accelerate and enhance the immunoprecipitation reaction, and Tween-20 surfactant to lower and stabilize the sample blank values. Grossly lipemic, icteric, or hemolyzed sera can be assayed. Values up to about 220 mg/L, for which the standard curve is linear, can be measured without sample dilution. Results by the proposed method and by radial immunodiffusion (r 0.989) or laser nephelometry (r = 0.957) correlated well. Analytical recovery averaged 101.3%. Within-, between-, and day-to-day CVs ranged from 0.9% to 3.5%, 0.8% to 5.5%, and 1.9% to 4.8%, respectively. The method is demonstrably superior to radial immunodiffusion or nephelometry. Any spectrophotometer that can measure turbidimetrically at 340 nm can be used.