Can Hoechst be used to stain bacteria?

Yes, Hoechst can be used to stain bacteria, although the staining is dimmer than that seen in mammalian cells. Live as well as dead bacteria can be stained with a Hoechst dilution of 12-15 µg/ml in PBS or 150 mM NaCl for 30 minutes at room temperature. Dead cells stain more brightly than live cells.