FIG. 9.

Saponin induces egress in a Ca²⁺-dependent manner. Intracellular parasites were induced to exit by treatment with either 0.005% saponin (a) or 1 μM A23187 (b) at 4°C for 20 min. After an additional 2 min of incubation at 37°C, the cells were fixed and stained. The influence of extraparasitic [Ca²⁺] on each treatment was examined by using either HBSS_c (1 mM Ca²⁺) or HBSS_nc (5 mM EGTA and no added Ca²⁺).