LABELING　McAb　3H11　AND　ITS　Fab　FRAGMENT　WITH　^（211）At　AND　THEIR　IMMUNOREACTIVITIES　AND　INJURY　EFFECTS　ON　HUMAN　GASTRIC　CANCER　CELLS

An antigastric cancer monoclonal antibody, 3H11, and its Fab fragment, were labeled using p-(211At)-astatobenzoic acid (pAtBA) intermediate, in the yields of more than 30%. The results of in vitro experiments show that 211At-3H11 and 211At-3H11Fab are stable, and have specific immunoreactivities and cytotoxic effects to human gastric cancer cell M85. The cytotoxic effects are dependent on the concentration of 211At-3H11 or 211At-3H11 Fab and obviously stronger than that of Na211At.