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CIL:7313*  Cite 

A high resolution, longitudinal section through one toxicyst and one bundle of microtubules (nematodesma) of the oral area of Didinium involved in the killing and ingesting of large prey. Didinium specializes in consuming Paramecium, an organism nearly their own size in less than one minute at standard room temperature. This slightly oblique longitudinal section allows the opportunity to visualize the longitudinal substructure of the hexagonally packed microtubules that support the cytopharynx and assistin the process. TEM taken on 5/20/69 by R. Allen with Philips 300 operating at 60kV. Neg. 6,370X. The raw film was scanned with a Nikon Coolscan 9000ED. This image is suitable for quantitative analysis. Standard glutaraldehyde fixation followed by osmium tetroxide, dehydrated in alcohol and embedded in an epoxy resin. Microtome sections prepared at approximately 75nm thickness. Additional information available at (

Biological Sources
NCBI Organism Classification
Didinium nasutum
Cell Type
eukaryotic cell
Eukaryotic Protist
Ciliated Protist
Cell Line
Carolina Biological Supply Company, NC, U.S.A.
Cellular Component
microtubule associated complex
extrusive organelle
Richard Allen
Digital Object Identifier (DOI)
Archival Resource Key (ARK)
Grouping This image is part of a group.
Image Type
transmission electron microscopy (TEM)
illumination by electrons
Image Mode
detection of electrons
Parameters Imaged
electron density
Source of Contrast
elastic scattering
Visualization Methods
stain with broad specificity
osmium tetroxide
uranyl salt
lead salt
Processing History
Data Qualifiers
raw, unprocessed data
suitable for spatial measurements
Spatial Axis Image Size Pixel Size
X 3504px 0.83nm
Y 7801px 0.83nm