Alternate header for print version

Attribution Non-Commercial; No Derivatives:This image is licensed under a Creative Commons Attribution, Non-Commercial, No Derivatives License. View License Deed | View Legal Code
*CIL – Cell Image Library accession number. Please use this to reference an image.

CIL:10904*  Cite 

This electron micrograph shows the P-face of a small region of membrane from the midpiece of guinea pig sperm. The changing distribution of intramembranous particles (IMPs)in this image provided some of the first evidence of local variation in the organization of the membrane. Linear arrays of IMPs in the lower region of the micrograph are closely associated with mitochondria. This image first appeared in Fawcett, International Cell Biology 1976-7, p 588-600, Rockefeller University Press, New York, and was reprinted with permission as Figure 6 from Chapter 1 (The Cell Surface) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. A PDF copy of the accompanying chapter is available on the ASCB's BioEDUCATE website.

Technical Details

With the freeze-fracture technique, tissue is rapidly frozen and cracked to shear along zones of weakness. Cleavage of membranes occurs along the hydrophobic interior of the lipid bilayer to reveal views of a "p-face" (the outwardly-facing inner half of the membrane) and an "e-face" (the inwardly-facing outer half of the membrane), and a metallic replica is made of the fractured surface. The intramembranous particles represent integral membrane proteins.

Biological Sources
NCBI Organism Classification
Cavia porcellus
Cell Type
Cellular Component
plasma membrane
extracellular region part
Biological Context
Biological Process
plasma membrane organization
Don W. Fawcett
ISBN 0721635849
The Cell, 2nd Ed. by D.W. Fawcett
Digital Object Identifier (DOI)
Archival Resource Key (ARK)
Grouping This image is part of a group.
Image Type
transmission electron microscopy (TEM)
Image Mode
illumination by electrons
detection of electrons
Parameters Imaged
electron density
Source of Contrast
differences in deposition of metal shadow
Visualization Methods
shadowing and plating
Data Qualifiers
processed data
Sample Preparation
Relation To Intact Cell
isolated subcellular component
Spatial Axis Image Size Pixel Size
X 922px ——
Y 1292px ——