Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

The Structure of Cytoplasm in Directly Frozen Cultured Cells. I. Filamentous Meshworks and the Cytoplasmic Ground Substance

P. C. Bridgman and T. S. Reese
The Journal of Cell Biology
Vol. 99, No. 5 (Nov., 1984), pp. 1655-1668
Stable URL: http://www.jstor.org/stable/1611100
Page Count: 14
  • More info
  • Cite this Item
The Structure of Cytoplasm in Directly Frozen Cultured Cells. I. Filamentous Meshworks and the Cytoplasmic Ground Substance
Preview not available

Abstract

Cultured fibroblasts or epithelial cells derived from Xenopus laevis embryos were directly frozen, freeze-substituted by an improved method, and then either critical-point-dried and viewed as whole mounts, or embedded and thin sectioned. In thin regions of these cells, where ice crystal artifacts are absent, the cytoplasm consisted of a dense, highly interconnected meshwork of filaments, embedded in a finely granular ground substance. The meshwork in directly frozen, intact cells was compared with that in cells that were lysed (physically, with detergents, or with filipin), or fixed with glutaraldehyde before freezing. Although filaments tended to be less numerous in lysed cells, their overall organization was the same as that in intact cells. However, fixation with glutaraldehyde before freezing distorted the meshwork to variable degrees depending on the osmolarity of the fixation buffer, and also obscured the granular ground substance which is obvious in directly frozen cells. With optimal preparative methods, the cytoplasm of these directly frozen cells is shown to consist of a cytoskeleton composed of discrete interwoven filaments interconnected by numerous finer filaments and a readily extractable granular matrix which presumably represents aggregations of cytoplasmic proteins.

Page Thumbnails

  • Thumbnail: Page 
1655
    1655
  • Thumbnail: Page 
1656
    1656
  • Thumbnail: Page 
1657
    1657
  • Thumbnail: Page 
1658
    1658
  • Thumbnail: Page 
1659
    1659
  • Thumbnail: Page 
1660
    1660
  • Thumbnail: Page 
1661
    1661
  • Thumbnail: Page 
1662
    1662
  • Thumbnail: Page 
1663
    1663
  • Thumbnail: Page 
[1664]
    [1664]
  • Thumbnail: Page 
1665
    1665
  • Thumbnail: Page 
1666
    1666
  • Thumbnail: Page 
1667
    1667
  • Thumbnail: Page 
1668
    1668