Purification of human C-reactive protein by barium sulfate and preparative agarose electrophoresis

A procedure is described for the purification of C-reactive protein (CRP) from human serum. The methods described take advantage of the barium sulfate adsorption property of CRP and the unique biophysical property of CRP migration during electrophoresis in agarose gels containing Ca2+. The purified CRP had an apparant molecular weight of 28,000 as determined by migration of the reduced protein during SDS polyacrylamide gel electrophoresis. The described procedure has the advantage of not requiring either molecular sieve or affinity chromatography for purification of homogenous CRP from human sera.