Is PI fixable in flow citometry? - (Jan/30/2014 )
After staining cells with propidium iodide (viablility), can we fix the cells with PFA for analysis later on?
I learned the time between PI addition and measurement should be relatively short, so I doubt storing the samples by fixing would be a good idea...in this thread here there is someone who apparently tried, though: https://lists.purdue.edu/pipermail/cytometry/2009-August/037730.html
The PI will be washed out with more and more washes/buffer changes, but it is certainly possible to PI stain, collect the samples again (if you have the right sort of FACS machine) and then subsequently fix and probe.
Note- I don't do FACS so not sure if this would be true - if you did PI staining and then fixed the cells, you should be able to still do live/dead immediately after fixing, as only the dead cells prior to fixing should have taken up the PI.