FIG. 3.

Effects of V. tubiashii cytolysin and erythrocyte concentrations on cytolysin-induced lysis of erythrocytes. Erythrocyte samples (1 ml) were incubated with the cytolysin, and the mixture was centrifuged to pellet unlysed erythrocytes. The absorbance of the supernatant fluids was measured at 545 nm and compared with that of the control. (A) Effect of cytolysin concentration. The control for this experiment was a saponin-lysed 0.35% (vol/vol) erythrocyte suspension. (B) Effect of erythrocyte concentration. The reaction mixture contained 2 HU of cytolysin and different amounts of erythrocytes. The controls for this experiment were saponin-lysed 0.175 to 3.5% (vol/vol) erythrocyte suspensions.