Radioimmunoassay of delta-toxin from B. thuringiensis: correlation with bioassay

A radioimmunoassay procedure, developed for delta-toxin of B. thuringiensis, is applicable to the assay of the toxin's bioactivity. When delta-toxin is inactivated to different degrees by heat treatment, the amount of toxin as determined by radioimmunoassay is proportionally decreased. It thus appears that the delta-toxin antibody may recognize and bind to the conformation in the molecule associated with its insecticidal activity.