
Utility of light scatter in the morphological analysis of sperm
Author(s) -
Zucker Robert M.,
Perreault Sally D.,
Elstein Kenneth H.
Publication year - 1992
Publication title -
cytometry
Language(s) - English
Resource type - Journals
eISSN - 1097-0320
pISSN - 0196-4763
DOI - 10.1002/cyto.990130108
Subject(s) - sperm , fluorescence , optics , biology , orientation (vector space) , biophysics , physics , mathematics , genetics , geometry
We were able to differentiate the morphologically diverse sperm nuclei of four animal species by using an Ortho flow cytometer to detect the forward light scatter from a red (helium‐neon) laser. Cytograms depicting the axial light loss and forward red scatter signals revealed unique, but reproducible, sigmoid distributions that reflected not only interspecies differences in shape and size, but variations in particle refractive index and orientation within the flow cell at the time of analysis. Consequently, we were able to use regional gating of the light scatter cytogram to minimize the influence of orientation on the resolution of the fluorescence signal. We also observed that sperm enlarging as a result of chemically induced decondensation exhibit over time a biphasic shift (increase, then decrease) in light scatter at a species‐dependent rate. These results suggest that, without any special adaptations to the flow cytometer, light‐scatter parameters can be used to discriminate morphologically different sperm, to enhance the resolution of fluorescence measurements that may otherwise be confounded by variability in radial orientation, and to detect alterations in the rate of a biochemical/biophysical process such as decondensation.