THE MEASUREMENT OF C-REACTIVE PROTEIN IN HUMAN SERA. COMPARISON OF THE CLINICAL TESTS ON THE BASIS OF A QUANTITATIVE METHOD

Abstract

A quantitative method for the detn. of C-reactive protein in human serum is descr. By the use of this procedure, a comparison has been made of the relative sensitivity of 2 qualitative methods applied to the measurement of this protein for clinical purposes. C-protein can be detected by a precipitin test with specific antiserum at concns. below 0.01 mg./ml.; a ring-test using pneumococcal C polysaccharide is not reliable at concns. below 0.1 mg./ml. C-protein is absent from normal serum, but in the acute phase of diseases such as rheumatic fever, concns. of 0.35 mg./ml. or greater are commonly encountered.