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Title: X-ray dense cellular inclusions in the cells of the green alga Chlamydomonas reinhardtii as seen by soft-x-ray microscopy

Technical Report ·
DOI:https://doi.org/10.2172/603459· OSTI ID:603459
; ;  [1]; ;  [2]
  1. Univ. of London (United Kingdom)
  2. Ernest Orlando Lawrence Berkeley National Lab., CA (United States)

Soft x-rays, having a greater ability to penetrate biological material than electrons, have the potential for producing images of intact, living cells. In addition, by using the so-called {open_quotes}water window{close_quotes} area of the soft x-ray spectrum, a degree of natural contrast is introduced into the image due to differential absorption of the wavelengths by compounds with a high carbon content compared to those with a greater oxygen content. The variation in carbon concentration throughout a cell therefore generates an image which is dependent upon the carbon density within the specimen. Using soft x-ray contact microscopy the authors have previously examined the green alga Chlamydomonas reinhardtii, and the most prominent feature of the cells are the numerous x-ray absorbing spheres, But they were not seen by conventional transmission electron microscopy. Similar structures have also been reported by the Goettingen group using their cryo transmission x-ray microscope at BESSY. Despite the fact that these spheres appear to occupy up to 20% or more of the cell volume when seen by x-ray microscopy, they are not visible by transmission electron microscopy. Given the difficulties and criticisms associated with soft x-ray contact microscopy, the present study was aimed at confirming the existence of these cellular inclusions and learning more of their possible chemical composition.

Research Organization:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
DOE Contract Number:
AC03-76SF00098
OSTI ID:
603459
Report Number(s):
LBNL-39981; ON: DE97007345; TRN: 98:009500
Resource Relation:
Other Information: PBD: Apr 1997; Related Information: Is Part Of Advanced light source: Compendium of user abstracts 1993--1996; PB: 622 p.
Country of Publication:
United States
Language:
English