title: An in vitro system for testing Bacillus thuringiensis toxins: the lawn assay.
abstract: A cell assay system was developed that allows Bacillus thuringiensis delta-endotoxins activated at high pH (10.5) to be tested in vitro without causing alkaline injury to target cells. The assay is carried out on a lawn of gel-suspended cells, requires only 1 microliter of sample per dose, and is quantitative, rapid, and sensitive. The threshold dose for toxicity of B. thuringiensis subsp. kurstaki HD-73 with IPRI-CF-1 cells was 24 pg protein. The assay is also very useful for identifying antibodies which inhibit toxicity and for detecting beta-exotoxin.
authors.affiliation: Forest Pest Management Institute, Sault Ste. Marie, Ontario, Canada.
authors.forename: J L
authors.initials: JL
authors.lastname: Gringorten
authors.forename: D P
authors.initials: DP
authors.lastname: Witt
authors.forename: R E
authors.initials: RE
authors.lastname: Milne
authors.forename: P G
authors.initials: PG
authors.lastname: Fast
authors.forename: S S
authors.initials: SS
authors.lastname: Sohi
authors.forename: K
authors.initials: K
authors.lastname: van Frankenhuyzen
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000032:analysis; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D001681:Biological Assay / Q000379:methods*; D002460:Cell Line; D004731:Endotoxins / Q000032:analysis*; D006460:Hemolysin Proteins; D007915:Lepidoptera
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis