Preparation of Monoclonal Antibodies Reactive to a Hallucinogenic Drug, Psilocin

The cultivation or trafficking of “Magic mushrooms,” containing hallucinogenic psilocin and psilocybin, has been prohibited by the Narcotics and Psychotropics Control Law in Japan since 2002. To identify these mushrooms, we attempted to prepare the monoclonal antibody (mAb) reactive to these hallucinogens. As an antigen inducing an anti-psilocin mAb, N-{4-[3-(2-dimethylaminoethyl)indol-4-yl-oxy]butyl}succinamic acid was synthesized by modifying the 4-hydroxyl moiety of psilocin and coupled to a carrier protein of keyhole limpet hemocyanin. BALB/c mice were immunized five times with the antigen emulsified with an adjuvant, and their spleen cells were fused with mouse myeloma cells. We obtained several hybridoma cells producing mAbs reactive to psilocin, from which four clones, BA631, CA231, KA422, and MA332 with a higher production of anti-psilocin mAb were selected by limiting dilution. Isotype of CA231 and KA422 mAbs were IgG2a and that of BA631 and MA332 mAbs were IgG1. Enzyme immunoassay (EIA) using BA631 mAb, revealed that BA631 cross-reacted with psilocin and dimethyltryptamine, but not with the other indole derivatives such as psilocybin, 4-hydroxyindole, tryptamine, and tryptophan. Therefore, these antibodies could be used for the identification of magic mushrooms.