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

CIL:34603*  Cite 

A cross section of cilium through the cilium-basal body complex extending from the cilium to the transition zone between the cilium and basal body and ending at the proximal tip of the basal body. In cross section the 9 + 2 axoneme of the cilium stands out. The plasma membrane covers the axoneme and is continuous with the plasma membrane covering the cell body. Each doublet tilts inward to the tangent of the axonemal cylinder. Two arms, an inner arm and outer arm, extend from the complete microtubule of each doublet. These arms have ATPase activity and are called dyneins. They cause one doublet to slide against the adjacent doublet. Other protein links, like the spokes, in the axoneme are elastic and induce the characteristic bending of the cilium and prevent excess sliding as the doublets slide past each other. TEM taken on 7/15/67 by R. Allen with RCA EMU3F operating at 50kV. Neg. 19,200X. Adapted with permission. The raw film was scanned with an Epson Perfection V750 Pro. This image is best used for quantitative analysis.

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. Additional information available at (

Biological Sources
NCBI Organism Classification
Tetrahymena pyriformis
Cell Type
cell by organism
eukaryotic cell
Eukaryotic Protist
Ciliated Protist
Cellular Component
cilium axoneme
Biological Context
Biological Process
cilium axoneme assembly
Richard Allen (University of Hawaii)
J. Cell Biol. 40:716-733, 1969
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
unprocessed raw data
Data Qualifiers
raw, unprocessed data
suitable for spatial measurements
Spatial Axis Image Size Pixel Size
X 604px 0.78nm
Y 886px 0.78nm