Studies on the Hemolytic Streptococcus

[摘要] A method is given for the preparation of a diffusate medium which supports the growth of 70 mgm. of hemolytic streptococci per liter. Each milliliter of filtrate from cultures of hemolytic streptococci of scarlatinal origin contained 10,000 skin test doses of erythrogenic toxin. The total erythrogenic toxic fraction was isolated and concentrated by adsorption on aluminum silicate (Lloyd's reagent) at pH 4.0, elution, ammonium sulphate precipitation, and dialysis. One milligram of substance was obtained per liter of filtrate. One skin test dose was equal to 0.0001 micrograms of substance which contained 10 per cent nitrogen and gave a positive test for carbohydrate. The purified toxin was less stable than the raw toxin of filtrate.Fractions which gave similar chemical tests, but which contained no erythrogenic toxin, were obtained by the same procedures from culture filtrates of two non-scarlatinal, non-erythrogenic strains of hemolytic streptococci.

[学科分类] 生物科学（综合）