Specific, antigenic protein of Guerin epithelioma.

Specific, antigenic protein of the molecular weight 61 000 and 66 000 and isoelectric point 5.15 were isolated from cytosol of Guerin epithelioma and antiserum against these proteins was obtained. These antigens appear to be specific for epithelioma. Such antigens were not found in any normal rat organ. Blood serum of Guerin epithelioma bearing rats does not contain antibodies against these antigens.