PI staining cell cycle analysis - (Apr/09/2014 )

I'm trying to perform an analysis of the cell cycle using the PI staining,:

i runned my n=1 samples and the obtained profile where quite strange,

So I runned my n=2 but after dilution of my cells and the shape obtained looks better.

Did someone observe the same phenomena? 

Did dilution cause a decrease of the DNA staining or I just dilute the signal due to the PI present as excess?

Could I dilute in the same way, samples that present a different number of cells? and treat each sample as a single entity?

thanks a lot

PI is not suitable for cell cycle analysis. It is mostly used for apoptosis.