Fig. 7. Anti-NSF Ab-fluorescence labeling of normal cells. Live cells were carefully permeabilized with saponin in the presence (A-D) or absence (E,F; controls) of ATP--S and NEM, fixed in formaldehyde, with Triton X-100 added for complete permeabilization, followed by anti-PtNSF Ab labeling, as outlined in Materials and Methods. In panels A-D several structures known to undergo multiple or individual vesicle fusions are labeled (for details, see text), for example, oral apparatus (oa), cytoproct (cp), outlets (cvo) of contractile vacuoles (cv) and onsets (arrowheads) of radial canals (rc) on these vacuoles, shown with variable labeling in different stages. In controls (E,F, without additives), the outlines of some of these structures can be vaguely seen with some residual fluorescence. Bars, 10 µm.