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

CIL:36646*  Cite 

The macronucleus is the largest organelle in the P. multimicronucleatum cell and can measure 35µm long by 12µm wide. A small fraction of a macronucleus is seen in this micrograph. The chromatin appears as thousands of small electron opaque foci scattered throughout a moderately stained nucleoplasm. In addition this nucleus contains numerous larger electron-opaque nucleoli scattered equally through the nucleoplasm. Nucleoli are sites of ribosome subunit synthesis. This cell was in day 1 of the culture age study and the cell had large regions of rough ER that were covered with large numbers of ribosomes. There were many folds in the macronuclear surface. The nuclear envelope is packed with nuclear pores. TEM taken on 5/29/78 by R. Allen with Hitachi HU11A operating at 75kV. Neg. 10,000X. Bar = 0.5µm.

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. Additional information available at (

Biological Sources
NCBI Organism Classification
Paramecium multimicronucleatum
Cell Type
cell by organism
eukaryotic cell
Eukaryotic Protist
Ciliated Protist
Cellular Component
nuclear pore
Richard Allen (University of Hawaii)
Digital Object Identifier (DOI)
Archival Resource Key (ARK)
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 2606px ——
Y 3000px ——