1989 年 38 巻 12 号 p. 513-515
CA 19-9 epitope (s) on carcinoembryonic antigen (CEA) was studied by a method designated the hybrid immunoradiometric-assay (hybrid IRMA) using solid phase CEA antibody as a capture of CEA molecule and radio-labeled NS 19-9 antibody as a detector. The radioactivities of the hybrid IRMA of respective sera with certain cancers differed from that of normal sera. The specific radioactivities of hybrid IRMA were not disappeared by washing with the reaction mixture containing Triton X-100 as a detergent. Treatments of the sample with neuraminidase or periodate diminished the specific bound radioactivities, like as a CA 19-9 antigen. Furthermore, the treatment of CEAs by PI-PLC had no effect to the radioactivities. Taken together, it was suggested that CEA sugar moieties contain CA 19-9 like epitope (s) .