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

CIL:36755*  Cite 

Paramecium caudatum is a peniculine oligohymenophoran ciliate that has numerous rows of cilia called kineties that run along the posterior to the anterior axis on the cell’s dorsal side but curve around the oral region on the cell’s ventral side and end to form the anterior and posterior suture lines that extend from the oral region to the tips of the cell. This is a cross-section of P. caudatum near its anterior end showing a layer of trichocysts that lie under the cell surface. The surface of the cell is sculpted into ridges and the cilia arise from the bases of the concave invaginations. Each concavity represents a section through one kinety so that in this micrograph approximately 58 kineties can be seen to surround the cell near its anterior end. At this low magnification one can also see large numbers of medium-opaque mitochondria near the cell surface and interspersed between the trichocysts. Collidine-buffered fixation. TEM taken on 1/18/74 by R. Allen with Hitachi HU11A operating at 75kV. Neg. 3,750X. Bar = 1µm.

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:39112) 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
cell cortex
Biological Context
Biological Process
cytoplasm organization
cortical cytoskeleton organization
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 3191px ——
Y 3363px ——