Which drug concentration should I use for apoptosis detection - (Apr/21/2011 )

Hello,
I am studying the putative anticancer activities of organometallic drugs. The first test I routinely run is to determine the concentration at which the compound reduces cell growth by 50 % by MTT (IC50). For me the question is: can I use this IC50 value to determine which concentration of this compound I should use to test its ability to trigger apoptosis instead of necrosis ? I ultimately would like to be able to compare this ability with various compounds, saying for example that compound 1 at 4 times its IC50 causes 20 % of the cells to undergo early apoptosis, whereas compound 2 at 4 times its IC50 causes 50 % of the cells to undergo early apoptosis.
I'm asking because it looks like for a given compound you can find tons of different testing conditions (concentration, time of exposure) in the literature, whithout clear standard comparison procedure.
Thanks in advance for your help,
olivier

But with MTT you can not see early apoptosis, you just check necrosis. You need to use something like annexin V to detect early apoptotic cells

laurequillo on Thu Apr 21 10:02:41 2011 said:

Actually, I first compare the cytotoxicity of my compounds by MTT test and I would like to be able to determine if they kill the cells via apoptosis or necrosis (based on annexin V binding of apoptotic cells). The question is: based on IC 50 value (determined by MTT) which concentrations should I use ?

bozava on Tue Apr 26 07:50:45 2011 said:

I have the same question about apoptosis. I want to know how to determine the concentration and treament time to investigate apoptosis. When you investigate apoptotic proteins like caspase-3, -8 and -9 by western blot, what time is reseasonable for it? we have to check it when most cells are died.