(a) A living spermatozoon, where the nucleus is positive for Hoechst (blue), a DNA marker ... (d) A moribund spermatozoon with double staining: PI and Calcein Violet.

Hoechst 33342 is one of the few live-cell ... methods that require cell fixation and permeabilization. Propidium iodide staining of DNA in fixed cells has been widely adopted in cell cycle ...