PI vs. 7-AAD Nuclear Staining
C.Reutelingsperger at BIOCH.RULIMBURG.NL
Mon Mar 18 09:47:05 EST 1996
For those of you, who are using Annexin V-FITC and propidium iodide to measure apoptosis and have
problems with dim PI positivity of viable and early apoptotic cells, you can wash your cells after
staining with Annexin V-FITC and PI.
Using the binding buffer coming with the APOPTEST-FITC kit of NeXins Research, the washing step will
not result in a significant decrease of cellular bound Annexin V-FITC.
Doing this you will miss a possibly interesting subpopulation, namely those cells that are about to enter
the secondary necrotic subpopulation. Those cells start to lose plasma membrane integrity without
having a fully lost barrier (a free passage of PI to the intracellular DNA) and represent a late phase of
So, it'll depend on your question whether or not to include a washing step following Annexin V-FITC and
propidium iodide staining.
More information about the Cytometry