DNA damage, cytotoxic effect and cell-cycle perturbation of Hoechst 33342 on L1210 cells in vitro

Cytometry. 1988 Jan;9(1):1-6. doi: 10.1002/cyto.990090102.


This study was designed to evaluate the effects of vital dye Hoechst 33342 (HO 33342), at concentrations used to obtain a good DNA histogram resolution, on DNA integrity, cell growth, and cell-cycle phase distribution of L1210 cells. HO 33342 exposure for 2 h, at 37 degrees C produced DNA single-strand breaks as assessed by the method of alkaline elution. DNA single-strand breaks were concentration dependent (in the range .5-5 micrograms/ml) and increased significantly when HO 33342 (0.5-1.5 micrograms/ml) was associated with exposure in a flow cytometer to U.V. laser beam illumination. HO 33342 produced a cytotoxic effect on cell growth even at the concentration of 0.5 microgram/ml--a concentration ten-fold smaller than those required to obtain a good DNA histogram resolution. HO 33342 produced a severe block of the cells in the G2-M phase of the cell cycle already evident 24 h after stain exposure and continuing up to 144 h after start of recovery. A new polyploid cell population (with a 4 c DNA content) not present in the unstained cells was already evident 24 h after dye exposure. The data shown in the present paper would imply caution in using sorted cells stained with HO 33342 dye for biological, biomedical, and pharmacological studies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Benzimidazoles / toxicity*
  • Cell Cycle / drug effects
  • Cell Line
  • DNA / drug effects*
  • DNA Damage*
  • Flow Cytometry
  • Lasers / adverse effects
  • Leukemia L1210 / pathology*
  • Mice
  • Ultraviolet Rays / adverse effects


  • Benzimidazoles
  • DNA
  • bisbenzimide ethoxide trihydrochloride