The history of venomous spider identification, venom extraction methods and antivenom production: a long journey at the Butantan Institute, São Paulo, Brazil

The article provides a historical report on venomous spider identification, venom obtainment methods and serum production at the Butantan Institute, São Paulo, Brazil. It is based on literature and personnal experience during the last 50 years. This result is the discovery that the real species causing potential severe human accidents were the spiders of the genus Loxosceles and Phoneutria.