Development of monkey C-reactive protein (CRP) assay methods

Monkey-specific C-reactive protein (CRP) assay methods (enzyme-linked immunosorbent assay (ELISA) and turbidimetric immunoassay (TIA)) were developed. The anti-monkey CRP serum was prepared by immunization of rabbits with the immune complex formed between the acute-phase serum from turpentine oil-inoculated monkeys and goat anti-human CRP serum. The specificity of the rabbit anti-monkey CRP serum was confirmed by immunoelectrophoresis and Western blotting. The purity of monkey CRP prepared by chromatography procedures was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The serum CRP levels in nine normal monkeys, as measured by sandwich ELISA were ranged from 0.26 to 1.42 μg/ml (mean 0.71±0.37). The CRP levels in five acute-phase sera of turpentine oil-inoculated monkeys were 248–451 μg/ml (mean 371.2±73.8). This monkey-specific CRP assay method was found more sensitive than the human-specific CRP assay method in detecting monkey CRP by TIA.