Abstract
The heat-labile toxin (HLT) of Bordetella pertussis was purified by column chromatography on DEAE-cellulose, salt fractionation and preparative acrylamide gel electrophoresis. The toxin obtained was confirmed to be free from hemagglutinins, protective antigens, histamin sensitizing factors, and K and O agglutinogens, and was shown to be homogenous by agar gel diffusion tests, ultracentrifugation, and electrophoresis. The minimal necrotic dose of the HLT in guinea pig was 0.01 μg dry weight. It was a protein in nature, contained a sugar moiety and possessed S value of 1.4. The toxicity of purified HLT was increased by mixing with a protein, such as rabbit serum.
