Light scattering and cell volumes in osmotically stressed and frozen-thawed cells.
Recent reports, indicating that under some conditions the intensity of light scattering from cells is a nonlinear function of cell volume, have led to the widespread generalization that intensity of low-angle light scattering indicates cell size. This study was performed to measure the relationships between light scattering and cell volumes in an-isotonic solutions and after a freeze-thaw stress. Cell volumes in isolated human lymphocytes, human granulocytes, and hamster fibroblasts were deliberately altered by exposure to anisotonic solutions. Boyle-vant Hoff plots of cell volume as a function of inverse osmotic pressure showed that the cells behaved as osmometers. Similar plots of right-angle and low-angle light scattering showed that the intensity of light scattering varied inversely with cell volume. In other experiments where cells were frozen without cryoprotectant at various sub zero temperatures to -25 degrees C and then thawed rapidly, cell viability decreased progressively with decreasing temperature, as did the intensity of both low-angle and right-angle light scattering, although cell volumes remained relatively constant. The intensity of both low- and high-angle light scattering varied inversely with cell volumes in hypertonic and hypotonic solutions, but cell damage induced by freezing and thawing resulted in significant reductions in the intensity of low-angle light scattering with little change in cell volume. These observations show that light scattering and cell volumes can vary independently, and they underline the need for a better understanding of the phenomenon of light scattering from living cells.
McGann
L E
LE
Department of Pathology, University of Alberta, Edmonton, Canada.
Walterson
M L
ML
Hogg
L M
LM
D000818:Animals; D006224:Cricetinae; D005347:Fibroblasts / Q000502:physiology / Q000648:ultrastructure*; D005434:Flow Cytometry; D005615:Freezing; D006098:Granulocytes / Q000502:physiology / Q000648:ultrastructure*; D006801:Humans; D008027:Light; D008214:Lymphocytes / Q000502:physiology / Q000648:ultrastructure*; D009997:Osmotic Pressure; D012542:Scattering, Radiation