3 replies to this topic

[bozava]

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

[laurequillo]

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

[bozava]

laurequillo, on 21 April 2011 - 02:02 AM, said:

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

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 ?

[Research]

bozava, on 25 April 2011 - 11:50 PM, said:

laurequillo, on 21 April 2011 - 02:02 AM, said:

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

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 ?

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.