Porosomes are cup-shaped supramolecular structures in the cell membranes of eukaryotic cells where secretory vesicles transiently dock in the process of vesicle fusion and secretion. The transient fusion of secretory vesicle membrane at a porosome, base via SNARE proteins, results in the formation of a fusion pore or continuity for the release of intravesicular contents from the cell. After secretion is complete, the fusion pore temporarily formed at the base of the porosome is sealed. Porosomes are few nanometers in size and contain many different types of protein, especially chloride and calcium channels, actin, and SNARE proteins that mediate the docking and fusion of the vesicles with the cell membrane. Once the vesicles have docked with the SNARE proteins, they swell, which increases their internal pressure. They then transiently fuse at the base of the porosome, and these pressurized contents are ejected from the cell. Examination of cells following secretion using electron microscopy, demonstrate increased presence of partially empty vesicles following secretion. This suggested that during the secretory process, only a portion of the vesicular contents are able...