Comparison of two automated quantitative immunoassays for the determination of C reactive protein concentrations.

Two quantitative, automated methods for the determination of C reactive protein (CRP) were compared: turbidimetry (Cobas Fara II, Roche, Welwyn Garden City, UK) and fluorescence polarisation TDx, Abbott, Wokingham, UK). One hundred and twenty routine serum samples submitted for measurement of CRP were tested using both procedures. The results were compared using regression line analysis and showed a high degree of correlation (r2 = 0.99, X coefficient = 1.01, constant = 0.11). C reactive protein can be accurately measured using the automated turbidimetric method which can be recommended as an alternative to fluorescence polarisation.