Cell-specific cytotoxicity expressed by a conjugate of ricin and murine monoclonal antibody directed against thy 1.1 antigen.

The isolation and characterization are described of a conjugate between ricin, and a thy 1.1-specific monoclonal IgG2a murine antibody synthesized using N-succinimidyl-3-(2-pyridyldithio)propionate. The conjugate selectively inhibited protein synthesis in Thy 1.1-positive (AKR SL3) mouse leukemia cells compared to Thy 1.2-positive (AKR/Cu SL1) cells.