use Hoechst instead of DAPI with 100ng/ml to 1ug/ml and PI 1ug/ml.
incubation will take ca 2hrs (live cells might not be stained properly otherwise). To set the right filtersets on your fluorescence microscope, for info see e.g. https://www.thermofisher.com/order/fluorescence-spectraviewer#!/ for the spectral properties of the dyes.
Dear Heiko Dussmann. Thank you for your reply and your suggestion. I will use Hoechst in my future test and share it, however, now I need to use PI and DAPI. So, I'm looking for protocol to use this staining for my cell culture.