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

CIL:36659*  Cite 

The appearance of the macronucleus depends on the stage of the cell, whether the cell is in early, middle or late growth phase or is in stationary phase or whether the cell is dividing by mitosis or is undergoing meiosis. In interphase the major changes will be observed in the nucleoli as the chromatin bodies maintain a relatively constant appearance. The nucleoli often exhibit a regular beaded appearance on the surface which is seen as regularly spaced threads when the nucleolus is sectioned through its surface. Presumably these represent stages in ribosomal subunit development prior to the separation of individual subunits for transport through the nuclear pores to the cytosol. TEM taken on 1/10/73 by R. Allen with Hitachi HU11A operating at 75kV. Neg. 16,900X. Bar = 0.25µm.

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
Biological Context
Biological Process
nucleolus organization
macronucleus organization
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 2679px ——
Y 3000px ——