Comparative evaluation of several DNA binding dyes in the detection of apoptosis-associated chromatin degradation by flow cytometry

Cytometry. 1992;13(2):137-43. doi: 10.1002/cyto.990130205.


Mouse thymocytes readily undergo apoptosis-associated DNA degradation upon exposure to glucocorticoids or ionizing radiation. It has been previously shown that flow cytometric cell cycle analysis of propidium iodide-stained apoptotic thymocytes results in the appearance of a distinct cell cycle region (the A0 region) below the G0/G1 region. Cells in this region were shown to be undergoing apoptosis, and determination of apoptosis by flow cytometric analysis was proposed as a superior method for evaluating thymocyte apoptosis. In this study, a variety of DNA binding dyes with diverse primary binding mechanisms were evaluated for their ability to detect glucocorticoid and ionizing radiation-induced apoptosis in mouse thymocytes. Apoptotic thymocytes stained with DNA binding dyes from the phenanthridinium, acridine, actinomycin, chromomycinone, anthracycline, and bisbenzimidazole groups all demonstrated clearly defined A0 regions with percentages comparable to those obtained for propidium iodide. These results indicate that the appearance of the A0 region is not dependent on a particular dye binding characteristic and may be the consequence of extensive changes in chromatin structure resulting in a significant degree of dye exclusion.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acridines / analysis
  • Acridines / metabolism
  • Acridines / standards
  • Animals
  • Benzimidazoles / analysis
  • Benzimidazoles / metabolism
  • Benzimidazoles / standards
  • Cell Death
  • Cells, Cultured
  • Chromatin / chemistry*
  • DNA / analysis
  • DNA / metabolism
  • DNA-Binding Proteins / analysis
  • DNA-Binding Proteins / metabolism
  • DNA-Binding Proteins / standards*
  • Dactinomycin / analysis
  • Dactinomycin / metabolism
  • Dactinomycin / standards
  • Flow Cytometry / methods
  • Fluorescence
  • Fluorescent Dyes / analysis
  • Fluorescent Dyes / metabolism
  • Fluorescent Dyes / standards*
  • Male
  • Mice
  • Mice, Inbred A
  • Thymus Gland / chemistry
  • Thymus Gland / cytology*


  • Acridines
  • Benzimidazoles
  • Chromatin
  • DNA-Binding Proteins
  • Fluorescent Dyes
  • Dactinomycin
  • DNA
  • bisbenzimide ethoxide trihydrochloride