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

CIL:36768*  Cite 

The highest concentration of parasomal sacs is found in the oral region associated with the three ciliary membranelles, called in Paramecium, the ventral amd dorsal peniculi and the quadrulus. This micrograph shows the four rows each of the two peniculi, dorsal and ventral, and a large accumulation of coated vesicles and early endosomal cisternae immediately below the basal bodies. Two rows of parasomal sacs border the closely packed peniculi and a third row separates the two peniculi. Four rows of parasomal sacs interdigitate with the 4 rows of more loosely associated cilia in the quadrulus. TEM taken on 1/25/74 by R. Allen with Hitachi HU11A operating at 75kV. Neg. 19,500X. Bar = 0.2µm.

Technical Details

Standard glutaraldehyde fixation followed by osmium tetroxide, dehydrated in alcohol and embedded in an epoxy resin. Microtome sections prepared at approximately 75nm thickness. The negative was printed to paper and the image was scanned to Photoshop. This digitized image is available for qualitative analysis. There is a high resolution version of this image in the library (CIL:39129) which is available for quantitative analysis. Additional information available at (

Biological Sources
NCBI Organism Classification
Paramecium caudatum
Cell Type
cell by organism
eukaryotic cell
Eukaryotic Protist
Ciliated Protist
Cellular Component
oral apparatus
cell cortex
early endosome
coated pit
Richard Allen (University of Hawaii)
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
uranyl salt
lead salt
osmium tetroxide
Processing History
recorded image
Print from negative scanned for Photoshop.
Data Qualifiers
processed data
Spatial Axis Image Size Pixel Size
X 2992px ——
Y 3446px ——