Bioassay Methods for Quantification of Bacillus thuringiensis δ-Endotoxin

Abstract

The historical development of Bacillus thuringiensis (BT) bioassays in Europe and the United States(US) are traced and the important milestones noted. The 1971 "official" U.S. lepidopterous bioassay and its 1982 revision are covered and bioassay quality control criteria explained. The development of each of the lepidopterous-active standards E-61, 1-S-1971, and 1-S-1980, are discussed. Diet-incorporation per os bioassays, surface contamination, Chauthani's hole-in-wax, and Hughes' droplet technique are described for use in lepidopteran assays. Various in vitro assays are contrasted with in vivo assays and their limitations discussed. The standards and assays of Bacillus thuringiensis var. israelensis are presented.