drug concentration - (Jun/06/2014 )

Hi,

I use a drug for my cancer cell line, but I cannot a convenient concentration for my experiments. After reading some papers, I used 7 concentrations; 10, 25, 50, 100, 125, 150 and 200 uM. Interestingly, I cannot take a decrease of cell proliferation towards to high concentrations, when I look into 200 uM, it is similar to control, but in others there is a little decreasing about 20%.

I used WST-1 for 3 hours and values reached to above 3. I made this experiment for 3 days and results are same for 3 days.

What can I do to find the convenient drug concentration range and then IC50 value?

Which drug (if it isn't one you are developing yourself)? It may be that you aren't leaving it long enough or that the line isn't susceptible.

It is SDX-105 and line is HL60.

The couple of papers I found relating to both HL60 and bendamustine indicate intermediate sensitivity, which according to this paper is about 150 uM (fig 1a).  IC80 looks like about 275, and these values were measured 72 hours post treatment.

Why can I find that results? Because of solvent? I have used water. Shall I use ethanol or DMSO?

So long as it dissolved, the solvent shouldn't have had any effect on the experiment.  It may be that you seeded too many cells for the drug to work effectively or that you made an error in the Wst1 assay?

I will check and configure them again