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

CIL:36607*  Cite 

In quick-freeze deep-etch preparations the plasma membrane can be seen to contain plaques or plates of intramembrane particles (IMPs) that are regularly aligned in rows with a center-to-center spacing between rows of 25nm. These plaques remain in the P-fracture face of the plasma membrane and are found mostly on the anterior ventral surface of the cell near the anterior suture. Their function is not known. For discussion see Allen, J. Ultrastruc. Res. 63:64-78, 1978 and Hufnagel, Micros. Res. Tech. 22:225-264, 1992. TEM taken on 5/26/92 by R. Allen with Zeiss 10A operating at 80kV. Neg. 19,800X. Bar = 0.25µm. There is a high resolution version of this image in the library (CIL:39314) which is available for quantitative analysis. Additional information available at (

Biological Sources
NCBI Organism Classification
Paramecium multimicronucleatum
Cell Type
cell by organism
eukaryotic cell
Eukaryotic Protist
Ciliated Protist
Cellular Component
plasma membrane
Biological Context
Biological Process
plasma membrane 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
electron density
Parameters Imaged
elastic scattering of electrons
electron density
Source of Contrast
differences in deposition of metal shadow
Visualization Methods
transmission electron microscopy (TEM)
Processing History
shadowing and plating
recorded image
Print of negative scanned for Photoshop
Data Qualifiers
processed data
Spatial Axis Image Size Pixel Size
X 2148px ——
Y 2675px ——