Alternate header for print version

Public Domain: This image is in the public domain and thus free of any copyright restrictions. However, as is the norm in scientific publishing and as a matter of courtesy, any user should credit the content provider for any public or private use of this image whenever possible. Learn more
*CIL – Cell Image Library accession number. Please use this to reference an image.

CIL:39755*  Cite 

Transmission electron micrograph showing the nucleus of a mouse cardiac tissue with nucleolus. At the center of the image is a large structure called the nucleus which is a membrane-limited compartment within the cell that contains the genetic material, DNA, in the form of chromosomes. Within the nucleus is the nucleolus is a small, darkly staining mass within the nucleus wherein ribonucleoprotein is produced. Within the nucleolus it is easy to see the four small circular areas called the nucleolar organizing region is initially where RNA and its associated proteins are processed.

Technical Details

Primary fixation included: 2.5 % glutaraldehyde, 2% formaldehyde in 0.1 M Na-phosphate buffer, pH 7.4. Post-fixed in 2% OSO4 in 0.1 M Na-phosphate buffer, pH 7.4. Stained en bloc in 1% uranyl acetate. The tissue was then dehydrated in a graded series of ethanol and infiltrated with Spurr’s resin. Thin sections of 70 nm were trimmed using a diamond knife and post-stained in uranyl acetate and lead citrate. This micrograph image was taken using a Phillips CM 100 transmission electron microscope at an accelerating voltage of 80kV.

Biological Sources
NCBI Organism Classification
Mus musculus
Cell Type
cardiac muscle cell
Cellular Component
nucleolus organizer region
Biological Context
Biological Process
nucleolus organization
Dee Lauzon
Sue Lancelle
Marian Rice
Mount Holyoke College
Digital Object Identifier (DOI)
Archival Resource Key (ARK)
Grouping This image is part of a group.
Image Type
recorded image
Image Mode
transmission electron microscopy (TEM)
Parameters Imaged
electron density
Source of Contrast
differences in adsorption or binding of stain
Visualization Methods
uranyl salt
lead salt
Processing History
unprocessed raw data
Sample Preparation
glutaraldehyde fixed tissue
formaldehyde fixed tissue
ethanol dehydration
tissue in epoxy resin embedment
Relation To Intact Cell
sectioned tissue
Spatial Axis Image Size Pixel Size
X 1805px ——
Y 1711px ——