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.

Fluorescence Ratio Imaging Microscopy: Temporal and Spatial Measurements of Cytoplasmic pH

Gary R. Bright, Gregory W. Fisher, Jadwiga Rogowska and D. Lansing Taylor
The Journal of Cell Biology
Vol. 104, No. 4 (Apr., 1987), pp. 1019-1033
Stable URL: http://www.jstor.org/stable/1612374
Page Count: 15
  • More info
  • Cite this Item
Fluorescence Ratio Imaging Microscopy: Temporal and Spatial Measurements of Cytoplasmic pH
Preview not available

Abstract

Fluorescence ratio imaging microscopy (Tanasugarn, L., P. McNeil, G. Reynolds, and D. L. Taylor, 1984, J. Cell Biol., 98:717-724) has been used to measure the spatial variations in cytoplasmic pH of individual quiescent and nonquiescent Swiss 3T3 cells. Fundamental issues of ratio imaging that permit precise and accurate temporal and spatial measurements have been addressed including: excitation light levels, lamp operation, intracellular probe concentrations, methods of threshold selection, photobleaching, and spatial signal-to-noise ratio measurements. Subcellular measurements can be measured accurately (<3% coefficient of variation) in an area of 3.65 μ m2 with the present imaging system. Quiescent Swiss 3T3 cells have a measured cytoplasmic pH of 7.09 (0.01 SEM), whereas nonquiescent cells have a pH of 7.35 (0.01 SEM) in the presence of bicarbonate buffer. A unimodal distribution of mean cytoplasmic pH in both quiescent and nonquiescent cells was identified from populations of cells measured on a cell by cell basis. Therefore, unlike earlier studies based on cell population averages, it can be stated that cells in each population exhibit a narrow range of cytoplasmic pH. However, the mean cytoplasmic pH can change based on the physiological state of the cells. In addition, there appears to be little, if any, spatial variation in cytoplasmic pH in either quiescent or nonquiescent Swiss 3T3 cells. The pH within the nucleus was always the same as the surrounding cytoplasm. These values will serve as a reference point for investigating the role of temporal and spatial variations in cytoplasmic pH in a variety of cellular processes including growth control and cell movement.

Page Thumbnails

  • Thumbnail: Page 
1019
    1019
  • Thumbnail: Page 
1020
    1020
  • Thumbnail: Page 
1021
    1021
  • Thumbnail: Page 
1022
    1022
  • Thumbnail: Page 
1023
    1023
  • Thumbnail: Page 
1024
    1024
  • Thumbnail: Page 
1025
    1025
  • Thumbnail: Page 
1026
    1026
  • Thumbnail: Page 
1027
    1027
  • Thumbnail: Page 
1028
    1028
  • Thumbnail: Page 
1029
    1029
  • Thumbnail: Page 
1030
    1030
  • Thumbnail: Page 
1031
    1031
  • Thumbnail: Page 
1032
    1032
  • Thumbnail: Page 
1033
    1033