2.2. C-Reactive Protein Assay

The C-reactive protein assay was performed by latex-enhanced immunoturbidometry. Fresh human blood samples were collected aseptically, separated by standard techniques and tested within 24 h of collection. The requested sample volume for the assay was 1.0 mL. Plasma was separated within 60 min of collection. All reagents were stored at the correct temperature and used before the manufacturer’s expiry date. All controls and samples were allowed to equilibrate to room temperature prior to use, gently mixed and then diluted. A diluted solution of the test sample is then mixed with latex particles coated with monoclonal anti-CRP antibodies. CRP present in the sample forms an antigen–antibody complex with the latex particles. The light scatter, measured by a turbidometric method (biochemical analyser COBAS c 501), is proportional to the concentration of C-reactive protein in the sample. Diagnostic reagents were supplied by Roche Diagnostics. A clinical laboratory program was used to transfer the sample results to the file. The reportable range of the method is 0.6–350 mg/L (5.7–3332 nmol/L). The lowest reportable CRP result is approximately 0.3 mg/L (2.9 nmol/L). For values above the linear range of the reaction, the automatic Rerun function is activated.