Two antigens cross-reactive with carc inoembryonic antigen (CEA) and distinct from the nonspecif ic cross-react ing antigen were identified in meconium by double immunodiffusion with a conventional goat ant i -CEA antiserum. These two antigens together competi t ively inhibited cross-react ing antibodies against them in CEA radioimmunoassay and contr ibuted to the measurement of meconium CEA le...