Apoptosis vs Viable Cells vs Necrosis (Annexin/PI Staining) - Which quadrants to sum up? (Jan/27/2011 )

Annexin V / Propidium Iodide Staining:

Viable Cells are in the lower left quadrant!
Apoptotic cells are in the lower right quadrant!

Do I have to sum up upper left & right quadrant to determine amount the necrotic cells??? Im not really sure!

thanks for advice

LL - live
LR- apoptotic (AnnexinV +PI-)
UR - late stage apoptotic (AnnexinV+PI+)
UL - necrotic (AnnexinV- PI+)

Denis Baev on Thu Jan 27 13:55:58 2011 said:

this was already clear for me before - but can i sum up the upper right (UR) and the upper left (UL) quadrant? I want to do some statistic analysis and graphs for excel!!

Nope. Necrotic cell % is UL only.
The sum of UL and UR % results the total % of dead cells (both necrotic and late stage apoptotic).

moljul on Fri Jan 28 08:08:11 2011 said:

I think conventionally that the UR quadrent is considered to be either late apoptotic or necrotic i.e. the assay cannot tell the difference. You could sum them both up if you really wanted to since they are both dead but it would probably be better to leave the UL quadrent separate since that is necrotic but not apoptotic so give a bit more information. If you want to tell the difference between late apoptotic and necrotic you may have to look at nuclear morphology or caspases etc.