Can propidium iodide be used on WBC nuclei with cell membrane removed - (Jun/16/2015 )

I want to count WBC from whole blood. To remove the RBC I have to use a lysis buffer that removes the cell membrane, leaving just the nuclei intact. I would like to use propidium iodide to get a viability count on the nucleus. Will that work since PI permeates DNA instead of the cell membrane like trypan blue?

PI-stained cells must be viewed immediately after staining. Otherwise everything turns orange. But RBC doesn't have nucleus. Or maybe I don't understand the question well.