This micrograph shows that the discoidal vesicles meet the cytopharyngeal membrane edge-on where they fuse. Besides the ribbon of 12 microtubules abutting the membrane there is a second small ribbon of 2 or 3 microtubules lying against the cytopharyngeal membrane on the posterior side of each ribbon. This narrow ribbon does not curve away from the membrane but remains close to the membrane and its termination marks the boundary line between the cytopharynx and the nascent vacuole membrane. TEM taken on 7/27/73 by R. Allen with Hitachi HU11A operating at 75kV. Neg. 12,750X. Published in J. Cell Biol. 63:904-922, 1974. Adapted with permission.
Standard glutaraldehyde fixation followed by osmium tetroxide, dehydrated in alcohol and embedded in an epoxy resin. Microtome sections prepared at approximately 75nm thickness. The raw negative was scanned with an Epson Perfection V750 Pro and this high resolution image is best used for quantitative analysis. Additional information available at (http://www5.pbrc.hawaii.edu/allen/).