Development of a highly sensitive latex reagent directed against C-reactive protein (CRP) using epitope analysis with monoclonal antibodies.

C-Reactive protein (CRP) is an acute-phase protein that increases during systemic inflammation and is currently one of the most frequently studied inflammatory markers in epidemiology. We have determined CRP concentration using novel latex reagent with polyclonal antibody. In the present study, we determined the concentration of CRP using monoclonal antibodies, and evaluated the interaction of antigen-antibody reactive sites and latex agglutination to detect low CRP concentrations. We developed four novel monoclonal antibodies that we classified into two major groups, and that were used to prepare the latex reagents. The latex reagents prepared using a cocktail of monoclonal antibodies for different epitopes appeared highly sensitive. The lower limit of CRP detection, which was defined using the mean 3 SD method, was calculated to be 5 ng/ml for the latex reagents when oligoclonal antibodies were utilized. Furthermore, the latex reagents were found to react specifically with CRP in clinical samples.