Detection of antibodies to embryonic antigens in sera of multiparous or colon tumor-bearing rats by a new indirect immunofluorescence assay

Abstract
An indirect immunofluorescence assay using antigen coupled to agarose beads detected high titers of antibody to embryonic antigens in sera from multiparous rats and rats bearing colon carcinomas. Sera from pregnant rats had antibody titers greater than 103 and some rats still had titers greater than 102 30 weeks after the end of pregnancy. Rats which developed colon carcinomas after treatment with 1,2-dimethylhydrazine were bled monthly between the end of treatment and detection of carcinoma. Antibody to embryonic antigens appeared in their sera at least 2 months before roentgenologic diagnosis of tumor.