An enzyme-linked immunoassay for detection of North American pit viper venoms.

We describe a method for immunodetection of North American pit viper venoms in clinical materials. Antibody-enzyme conjugates prepared against venoms of the western diamondback rattlesnake (Crotalus atrox), Mojave rattlesnake (Crotalus scutulatus), and copperhead (Agkistrodon contortrix) detect homologous venoms in concentrations of 0.1-.01 mcg/ml using a double antibody sandwich technique. Venoms of 10 additional species of U.S. pit vipers were detected in concentrations of 10 mcg/ml or less. Venoms of 4 species could not be detected at levels likely to be encountered in clinical situations. There are extensive cross-reactions between venoms of certain species, hence specific identification of a given venom cannot always be made. Venom usually can be detected at injection sites of experimental animals receiving intramuscular doses of 0.5-1.5 mg of venom but can rarely be detected in urine or plasma specimens. Venom was readily detected in specimens from experimental animals bitten by pit vipers of 6 species. The method is relatively rapid, simple, and inexpensive.