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*CIL – Cell Image Library accession number. Please use this to reference an image.

CIL:12299*  Cite 

A dividing Didinium nasutum. This large ciliate is capable of engulfing Paramecium. It has a thick ectoplasm containing numerous mucocysts embedded in its extensive epiplasm. Its external surface is coated with a layer of bacteria in this dividing cell. The cytoplasm is relatively compact under the conditions of fixation used. Electron opaque vacuoles are scattered in the cytoplasm. (For a more detailed report see Wessenberg and Antipa, Protistologica 4:427-447, 1968). TEM taken on 5/9/69 by M. Sage with Philips 300 operating at 60kV. Neg. 3,120X. Bar = 2µm.

Technical Details

The negative was printed to paper and the image was scanned to Photoshop. This digitized image is available for qualitative analysis. A high resolution view suitable for qunatitative analysis is available in the library (CIL:38862). 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
cell by organism
eukaryotic cell
Eukaryotic Protist
Ciliated Protist
Cell Line
Carolina Biological Supply Company, NC, U.S.A.
Cellular Component
cell cortex
M. Sage
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
stain with broad specificity
Visualization Methods
stain with broad specificity
osmium tetroxide
uranyl salt
lead salt
Processing History
recorded image
Print from negative scanned to Photoshop.
Data Qualifiers
processed data
suitable for spatial measurements
Spatial Axis Image Size Pixel Size
X 2805px ——
Y 3744px ——