You have drug X and dissolve it in DMSO at a concentration of 100 mg / mL. Your goal is to create an aliquot of this drug with a final concentration of 200ug/mL. The solvent you will use to dilute it is cell culture media. Is it possible to create this aliquot while keeping DMSO below 0.1% v/v? I have tried this and could not get it below 0.2%. If anyone can please help and show how they arrived at the answer I would really appreciate it!