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This section represents one in a series of serial sections. At this point the two parts of the macronucleus are now connected by a DNA replication band similar to the hypotrichs (e.g. Euplotes). The level of this section is approximately half way through the cell. The buccal cavity is reduced and the cytopharynx with its lamellae next to the paroral kinety is curved. Portions of 4 perioral membranelles are seen as well as a food vacuole. TEM taken on 3/12/71 by R. Allen with Hitachi HU11A operating at 75kV. Neg. 3,800X. Bar = 2µm. Standard glutaraldehyde fixation followed by osmium tetroxide, dehydrated in alcohol and embedded in an epoxy resin. Microtome sections prepared thicker to accommodate the series. Additional information available at (

Biological Sources

NCBI Organism Classification
Halteria grandinella
Cell Type
cell by organism
eukaryotic cell
Eukaryotic Protist
Ciliated Protist
Cell Line
Carolina Biological Supply Co., NC, U.S.A.
Cellular Component
oral apparatus
food vacuole

Biological Context

Biological Process
macronucleus organization
replication of DNA
DNA strand elongation


Richard Allen


This image is part of a group.


Image Type
transmission electron microscopy (TEM)
illumination by electrons
Imaging Mode
detection of electrons
Parameters Imaged
electron density
Source of Contrast
stain with broad specificity
Visualization Methods
stain with broad specificity
osmium tetroxide
uranyl salt
lead salt
Processing History
recorded image
Print scanned for Photoshop
Data Qualifiers
processed data
suitable for spatial measurements


Spatial Axis Image Size Pixel Size
X 1688px ——
Y 1746px ——
*CIL – Cell Image Library accession number. Please use this to reference an image.