Efficient preparation of monospecific anti-canine C-reactive protein serum and purification of canine C-reactive protein by affinity chromatography.

The canine C-reactive protein (CRP) fraction isolated from canine acute-phase serum on a phosphorylcholine-Sepharose 4B column was further subjected to Sephacryl S-300 gel filtration. A canine CRP fraction not containing IgM was then obtained. The antisera, obtained after several immunizations with this canine CRP fraction, contained nonspecific antibodies that reacted with albumin, transferrin and IgG in addition to CRP. This antiserum could be easily changed to monospecific canine CRP serum, when it was subjected to absorption for only 15 min using glutaraldehyde-insolubilized normal canine serum protein containing 3.5 micrograms ml-1 of CRP. Pure canine CRP was isolated with a recovery rate of 95% from canine acute-phase serum by affinity chromatography using specific anti-canine CRP antibody.