Question: Suppose You want to add PMA to 15mL of HL-60 cells so that you have a concentration of 5nM. Your stock solution is 1uM. What is the volume of the stock solution you need?

Question: The molecular weight of vincristine, a pharmaceutical drug, is 923.04. It is supplied in 1 mg per vial. You want to treat your culture cells with a final concentration of 2.5nM vincristine and will need 5mL of cells for your experiment. You only want to add 2uL of vincristine solution to your cells. What concentration should you make your stock solution of vincristine in order to make this 2uL addition?