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

CIL:9921*  Cite 

An image of the micronucleus and macronucleus of Opercularia coarctata. The nuclear envelope has numerous pores, at least as many per unit length as in the macronucleus. Some areas of the outer membrane of the micronucleus envelope bare ribosomes. TEM taken on 6/11/69 by R. Allen with Philips 300 operating at 60kV. Neg. 23,200X. Bar = 0.5µm. A print of the negative was scanned and processed in Photoshop. This image is best used for qualitative analysis. A high resolution image (CIL:7337) is available for quantitative analysis. Standard glutaraldehyde fixation followed by osmium tetroxide, dehydrated in alcohol and embedded in an epoxy resin. Microtome sections prepared at approximately 75nm thickness. Additional information available at (

Biological Sources
NCBI Organism Classification
Opercularia [NCBITaxon:168247]
Opercularia coarctata
Cell Type
cell by organism
eukaryotic cell
Eukaryotic Protista
Ciliated Protista
Cell Line
Cambridge Culture Collection, Cambridge, England, # LB1657/1
Cellular Component
nuclear pore
Biological Context
Biological Process
micronucleus organization
macronucleus organization
nucleocytoplasmic transport
membrane bound ribosomes
Richard Allen
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
detection of electrons
Parameters Imaged
electron density
Source of Contrast
stain with broad specificity
Visualization Methods
stain with broad specificity
osmium tetroxide
uranyl salt
lead salt
Processing History
recorded image
Print of negative scanned for photoshop
Spatial Axis Image Size Pixel Size
X 2893px ——
Y 3582px ——