 For quantitative cell cycle analysis, cells are usually fixed with ethanol and stained with DNA-binding dyes like propidium iodide, Hoechst 33342, DAPI, 7-Aminoactinomysin D, Mithramycin, DRAQ5, or TO-PRO-3, allowing for determination of phase by DNA quantity.However, if these cells have been fixed, they are dead and cannot be maintained for continued growth.Cells can also be resuspended in media and dyed with non-toxic dyes to maintain living cultures.