Try making a solution of 1 micromolar. 0.01 Molar is equal to 10uM, so... (X ul) (10uM)=(1000uL)(1uM) Basically.. how may microliters (X uL) of 10uM solution (10uM) do I need to make 1000uL to be 1uM? = add 100uL of your drug to 900uL of solution (DMSO, media, water, whatever). Now you have 1mL of a 1uM solution.

Then... 1mM is equal to 1000nM (X uL)(1000nM)=(2000uL)(50nM) So how many microliters of your 1uM solution do you need to make 2000uL to be 50nM?

(50/1000)*2000= 100uL.

If that's too much, try a higher concentration at the beginning. (Change diluting your 0.01M solution to 5mM or something).

Hope this makes sense, I've been drinking.