Fig. 5. Electron microscopic evidence that purified latex bead-containing phagosomes are free from contamination by other organelles. Latex bead-containing phagosomes were purified as described in the Materials and Methods section and thin sections (Buczynski et al., 1997) were examined using a transmission electron microscope. Arrow points to a multiparticle phagosome; arrowhead points to a single particle phagosome.