Application of x rays to the analysis of DNA packaging in mammalian sperm

Rod Balhorn, Michele Corzett, Michael J. Allen, Catherine Lee, Troy W. Barbee, Jeffrey A. Koch, Brian J. MacGowan, Dennis L. Matthews, Stan J. Mrowka, James E. Trebes, Ian McNulty, Luiz B. Da Silva, Joe W. Gray, Erik H. Anderson, D. Kern, David T. Attwood

Research output: Chapter in Book/Report/Conference proceedingConference contribution

8 Scopus citations


X-ray microscopy has been performed on unlabeled and gold labeled rat sperm nuclei using a tantalum x-ray laser (44.83 angstrom) and an x-ray zone plate lens. Transmission images of nuclei labeled with gold using an antibody to protamine 1 show large clusters of gold as well as individual 400 angstrom gold particles coating the surface of the chromatin. Images of the same nuclei obtained with a scanning x-ray microscope demonstrate that the initial exposure of the sperm nucleus to a photon intensity of 3.0 × 1014 W/cm2 for a duration of 500 ps did not destroy or grossly distort their structure. Other nuclei labeled with an antibody to protamine 2 were partially decondensed during the labeling process and contained large vacuole-like regions. Images were also obtained of unlabeled sperm nuclei. Data obtained from one unlabeled nucleus imaged with both the atomic force and x-ray laser microscopes was used to determine the thickness of the chromatin and estimate the amount of water that must be associated with the DNA-protamine complex in air-dried nuclei. These results suggest that even air-dried sperm nuclei are extensively hydrated and that tightly bound water may comprise as much as one-third of the volume of the dried sperm nucleus.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
PublisherPubl by Int Soc for Optical Engineering
Number of pages12
ISBN (Print)0819409146
StatePublished - Jan 1 1993
Externally publishedYes
EventSoft X-Ray Microscopy - San Diego, CA, USA
Duration: Jul 19 1992Jul 21 1992

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherSoft X-Ray Microscopy
CitySan Diego, CA, USA

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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