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

CIL:437*  Cite 

Transmission electron micrograph of unstained cryo-section of a sperm cell of the starfish Patiria miniata. Echinoderm sperm nuclei are unusual in that chromatin fibers are clearly seen, allowing their diameter to be accurately determined. Cryosections of frozen material are typically of low contrast and show defects such as knife marks and compression. Despite these defects, individual chromatin fibers are clearly visible, some spilling out from the nucleus. A portion of a mitochondrion is seen at upper right.

Technical Details

Whole sperm from the starfish P. miniata were cryo-fixed by plunging into liquid ethane, thin cryosections prepared, and examined in the frozen hydrated state using a Philips CM12 TEM operated at 80KV. Low dose images were recorded on SO-163 film. See also: Woodcock CL 1994 Chromatin fibers observed in situ in frozen hydrated sections. Native fiber diameter is not correlated with nucleosome repeat length. J Cell Biol 125:11-9.

Biological Sources
NCBI Organism Classification
Patiria miniata
Cell Type
Cellular Component
male germ cell nucleus
Biological Context
Biological Process
nucleus organization
chromatin organization
Chris Woodcock
Digital Object Identifier (DOI)
Archival Resource Key (ARK)
Grouping This image is part of a group.
Sample Preparation
unfixed tissue
cryofixed tissue
Relation To Intact Cell
microtome-sectioned tissue
Spatial Axis Image Size Pixel Size
X 3218px 1.2nm
Y 2219px 1.2nm