The toxin, ricin (0.4 microg/microl), was exposed to a range of sodium hypochlorite concentrations. SDS PAGE showed that hypochlorite caused the ricin to smear and decrease in mobility and, ultimately, caused a loss of silver staining. Cytotoxicity assays using dye uptake by Hep2 cells showed that treatment with 3 mM hypochlorite inactivated the ricin. Western blotting and ELISAs showed that binding by polyclonal antibodies raised against native ricin, or partially degraded ricin, diminished as hypochlorite degradation of the ricin increased.