A radioimmunoassay for tallysomycin.

Antibodies were raised against a new antineoplastic agent, tallysomycin, for use in a radioimmunoassay. The assay was sensitive to 2.5 ng of tallysomycin, had a coefficient of variation of 10.5% at 50 ng/ml, and was highly specific for tallysomycin A. The antibody exhibited reduced cross-reactivity with closely related tallysomycin analogs and little or no immunoreactivity with other antitumor antibiotics including bleomycin and phleomycin. Increased immunoreactivity occurred following copper chelation of tallysomycin B as compared with the non-chelated forms, thus indicating possible conformational alterations upon metal binding.