Purification of mouse alpha-foetoprotein by ampholyte displacement chromatography

Mouse alpha-foetoprotein (alphaFP) was isolated from H4 hepatoma tissue using Con A-Sepharose salt gradient ion exchange chromatography and ampholyte displacement chromatography, the latter being a new method for a sharp separation of proteins based on their different isoelectric point. The purity of the alphaFP was demonstrated by (i) the absence of contaminant on sodium dodecyl sulphate polyacrylamide gel electrophetic gels, (ii) Ouchterlony's immunodiffusion against monospecific antimouse alphaFP and the absence of precipitation against a polyvalent antinormal mouse serum, (iii) the production of a monospecific antiserum in a rabbit after injection of the purified antigen, and (iv) immunological unreactivity of the produced antiserum against normal hepatic tissue.