In quick-freeze deep-etch preparations the plasma membrane can be seen to contain plaques or plates of intramembrane particles (IMPs) that are regularly aligned in rows with a center-to-center spacing...

The infraciliary lattice in this quick-freeze deep-etched image consists of a meshwork of branching fibers composed of many subfibers. Basal bodies and trichocyst tips extend through the openings of t...

Quick-freeze deep-etch rotary-shadowed replica of a portion of the chemically-unfixed cytopharynx. The cytopharynx is continuous with the plasma membrane and is covered by only one membrane which is p...

Secondary lysosomes in quick-freeze deep-etch images lie against the smooth E-face of a phagoacidosome (DV-II) membrane. The P-fracture face of one fairly large lysosome lies close to the DV-II but no...

The infraciliary lattice in this quick-freeze deep-etched image consists of a meshwork of branching fibers composed of many subfibers. Basal bodies and trichocyst tips extend through the openings of t...

The cytoplasm of P. multimicronucleatum like all other cells contains a large number of organelles that are membrane bound. Membranes are used to compartmentalize and isolate metabolic and enzymatic p...

Quick-freeze deep-etch image of an unfixed and fractured mitochondrion. The tubular cristae average 50nm in diameter. Each cristae bears a helically arranged double row of particles with the particles...

The carrier vesicles dock with the acidosomes and then fuse with these larger vesicles before or as the vesicles dock at the nascent Digestive Vacuole. Thus the contents of the carrier vesicles are fi...

A favorable view of one trichocyst docking site in a quick-freeze deep-etch image shows the prominent outer ring of 37 IMPs and about the same number of IMPs in the inner ring more deeply embedded in ...

The P-face of the ciliary membrane at the base of the cilium has 9 triple rows of IMPs in register with the 9 doublets of the internal axoneme. It is thought that these IMPs may be sites of calcium in...