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

CIL:36225*  Cite 

The acidosome-like vesicle has at least 2 enclosing membranes or one membrane indented back on itself and an internal electron-opaque tongue-like droplet that is continuous with the enclosing membranes at one end of the vesicle and may arise by invagination of these membranes into the vesicle’s interior. Such vesicles do not resemble lysosomes of any other organism, including Paramecium. Lysosome membranes should be thicker and be coated by a heavy glycocalyx and exhibit latency. There is no glycocalyx seen here. TEM taken on 8/15/67 by R. Allen with Philips 200 operating at 60kV. Neg. 19,200X. Bar = 0.5µm. The negative was printed to paper and the image was scanned to Photoshop. This digitized image is available for qualitative analysis. There is a high resolution version of this image in the library (CIL:39722) which is available for quantitative analysis. Additional information available at (

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. Additional information available at (

Biological Sources
NCBI Organism Classification
Tetrahymena pyriformis
Cell Type
cell by organism
eukaryotic cell
Eukaryotic Protist
Ciliated Protist
Cellular Component
organelle membrane
Biological Context
Biological Process
digestive system process
Richard Allen (University of Hawaii)
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 from negative scanned
Data Qualifiers
processed data
Spatial Axis Image Size Pixel Size
X 3094px ——
Y 3824px ——