Open AccessIncreased membrane permeability of apoptotic thymocytes: A flow cytometric study
Author(s) -
Ormerod Michael G.,
Sun XiaoMing,
Snowden Roger T.,
Davies Reginald,
Fearnhead Howard,
Cohen Gerald M.
Publication year - 1993
Publication title -
cytometry
Language(s) - English
Resource type - Journals
eISSN - 1097-0320
pISSN - 0196-4763
DOI - 10.1002/cyto.990140603
Subject(s) - apoptosis , flow cytometry , thymocyte , fluorescein , biology , microbiology and biotechnology , staining , membrane permeability , membrane , chemistry , fluorescence , immunology , biochemistry , t cell , genetics , physics , immune system , quantum mechanics
We have recently developed a method for the separation and quantification of viable apoptotic cells without the need for permeabilisation or fixation of the cells. The method is based on the observation that apoptotic rat thymocytes fluoresce more brightly than normal cells after a brief incubation with the DNA binding dye, Hoechst 33342. In order to understand these differences, we have investigated the uptake of Hoechst 33342 by normal and apoptotic thymocytes. By staining with fluorescein diacetate, we have shown that the efflux of fluorescein from apoptotic cells is more rapid than that from normal thymocytes. This result demonstrated an increase in the permeability of the plasma membrane of the apoptotic thymocytes and it is this change which probably results in the more rapid uptake of Hoechst 33342. The data also revealed two populations of apoptotic thymocytes. © 1993 Wiley‐Liss, Inc.