Development and performance of a fully automated method for assay of C-reactive protein in the aca discrete clinical analyzer.

A quantitative immunoassay for C-reactive protein (CRP) has been developed for use in the Du Pont aca discrete clinical analyzer. Particle-enhanced turbidimetric immunoassay (PE-TIA) technology is used. The method has a CV of less than 10% in the range 2 to 120 mg/L. Neither hemolyzed samples (Hb less than 5 g/L), icteric samples (total bilirubin less than 300 mg/L), lipemic samples (triglyceride less than 15 g/L), nor some commonly used drugs interfere. Dithioerythritol is used to eliminate interference from rheumatoid factor. Good correlation was seen when the Du Pont CRP method was compared with the Beckman ICS, Syva EMIT, TDx, and Behring methods for CRP. The normal reference interval is 0 to 9 mg/L. The method, which is fully automated, is fast, requires only a few microliters of serum, and is well suited to emergency-room requirements.