Conversion of units please help..for IC50 - (Oct/06/2013 )

Hi I woukd like to know how  to exactly convert 20 ug of captopril  used for inhibition activity to nanogram/litre amount..I have a vague idea ......please let me know if I am in the right direction....

(amount use in ug / (molecular weight in (ug/ugmole) * amount ofreaction volume in ml)= ug mole/ml

and then I can convert to nanogram/litre is it right?? please let me know...soon ..

What can moles have to do with this. You have grams, you need grams/liter. Nowhere do moles come into the calculation. And what, pray tell, is the unit ug/ugmole?

It is very simple. You have 20 ug of captopril. You add it to some liquid (say 10 ml). The solution is now at a concentration of (20 ug)/(0.01 liters) =2000 ug/liter = 2e6 nanograms/liter.

No moles anywhere to be seen. Not even to be whacked.

Hey sorry..ug is ( μ grams) and I  asked the question wrong if I want to convert it to  μmolar...the formula I have given is it right ?just wanted to enquire.. I understand conversions can be made..thank you.

So do you want nanomol/litre or umol/litre?

Not that it makes much difference... the easiest way to convert these things is to do it in two separate equations, both very simple:

n=m/mr (number of moles = mass/molar mass)

and

c=n/v (concentration= number of mol/volume)

Thanks a lot everyone for the response :)