Dilutions..... - How to do dilutions (May/19/2008 )

Hey,

Just wondering if someone could tell me, is diluting some thing from micorgrams to nano grams the same as a molar dilution? If I have an 100 microgram/ml stock and want to get it down to 100ng/200micro liters can I just do a 1 in 1000 dilution (25 microliters in to 25 mls) and then take my 200 micro liters from there? Will the 200 from the 25mls still be 100ng?

Thanks!