Detection of T-2 toxin by an improved radioimmunoassay.

T-2 toxin in serum, urine, and saline was analyzed by a modified radioimmunoassay procedure. The specimens were added directly to the assay tubes without extraction steps. The reaction between antibody and ligands was optimal at 1 h. Albumin-coated charcoal was used to separate bound from free radioactivity. Quenching, which occurred with hemolyzed specimens, was corrected by a wet oxidation process with 60% perchloric acid and 30% hydrogen peroxide. The shorter incubation times resulted in an assay that takes less than 6 h to complete. The average affinity constant of the antibody (Km) was 1.75 X 10(10) liters/mol. The sensitivity was 1 ng per assay or 10 ng/ml. Among the other trichothecenes tested, only H-T-2 cross-reacted significantly (10.3%).