1983 年 27 巻 6 号 p. 349-354
Cellulose acetate membrane isoelectric focusing (CAIEF) of streptolysin O from Group A streptococci and direct detection method of hemolytic activity by red blood cell agar layering after focusing are described. Eleven hemolytic components from concentrated culture filtrate were detected which had pI values of 4.8, 5.0, 5.3, 5.4, 5.6, 5.9, 6.4, 6.6, 6.9, 7.2 and 7.4. Sensitivity of the direct detection method of hemolytic activity was examined with pI 6.5 hemolytic component prepared by preparative gel isoelectric focusing. This method was extremely sensitive, which was possible to detect 0.4 HD50 of streptolysin O. These methods were applied to the analysis of the fractions obtained by preparative polyacrylamide or Sephadex gel isoelectric focusing of concentrated culture filtrate. Reproducibility of pI value in CAIEF was comparable to that in polyacrylamide gel isoelectric focusing. The method is inexpensive and enables easy detection of hemolytic toxin.