Assay for determining the IC50 of a drug! - (Sep/20/2004 )

HI there,

I am confused that most of the researchers to investigate the IC50 of a particular drug will consider to use "serum free medium". After obtaining the IC50 concentration, they did not mention whether they were using serum free medium to perform other assay, such as Cell cycle assay...! I am concerning the issue that when to use serum free medium is suitable? Such that if you perform the Cell cycle assay by using the serum-free medium, would that be adding extra pressure to the cells, or the cells might have already arrested by lacking of nutrients?

I am not sure whether I should perform all different assays for the same condition - serum-free medium? such as to perform Cell cycle assay, proliferation assay, IC50 determination, ...etc.???????

Thanks you for you attention!

Pine

Hi Pine

When I tested a receptor for its EC50, I used media with 0,1 % serum, since it did not disrupt the assay, and since the cells then could survive without growing. The ligand was dissolved i PBS 0,1%serum.
But I did not use a cell cycle assay, I tested wether the receptor was activated, by measuring second messenger.
I do not know much about IC50 assays.

Regards Caro