I am trying to see cell death in Saccharomyces cereviciae through flow citometry and propidium iodide staining. Unfortunately viable cells also stains very rapidly with propidium iodide (treatment: 2 ug/ml PI for 1 minute). Somebody can advise me?
I resuspend the cells in phosphate buffer 100 mM pH7. Maybe this buffer affects yeast cell membrane?