Stimulating/Drugging Mammilian Cells - What is the proper way to add drugs or stimulants to a cell culture? (Nov/05/2009 )

Does anybody know the proper way to stimulate a mammalian cell culture with drugs?
I am using well plates, and am unsure if I should add the drug directly to each well containing medium (e.g., a 1:100 dilution of pre-diluted drug in DMSO to DMEM), or I have also read a proper way to do it is make a stock solution of drug in the medium using a 1:1000 drug:DMEM dilution.
If anyone has experience, please help. These are kinase inhibitors.

Eagles09 on Nov 5 2009, 04:01 PM said:

Hi,

If you are working with a chemical as toxic to cells as DMSO is, I would advise making a high concentration stock in DMSO and then bringing the concentration down, into aliquots, using your media of choice (DMEM). This will ensure your cells are exposed to as little as possible of DMSO.

Some people arent able to further dilute their drugs if they are only soluble in organic colvents like methanol. Im working on a drug which is soluble in methanol but when I add 10 microlitres into 990 microlitres of water, it quickley precipitates out.

I would mix the drug in a volume of medium and then add to the wells rather than adding individually. In an ideal world, there would be no difference, but in practice, there will be minute differences in the volume of medium in each well and differences in each pipetting so you will end up with varying concentrations.

Thank you for the responses. I did perform an experimental screen diluting the stock concentration of drug into a larger volume of media and then distributing, and this seemed to be effective, as you are both confirming. So, I will stick with this method. Agreed about the pipetting inaccuracies, but until robotics is standard (and therefore more available), there isn't a good way to get around it! I always think to myself how in 30 years from now I will teach a class and jokingly tell my students how lucky they are because we used to have to pipette manually