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What concentration and how much should I add? (Leupeptin) - Calculations, calculations, calculations... (Mar/10/2011 )

Hi there

I have a stock solution of Leupeptin of 2mg/ml.
I want to add 200 uM to my cells.

At the end of the day, I don't know what concentration and how much I need to get 200 uM of Leupeptin.
Here is the information regarding Leupeptin

Can anyone help out?
Sorry, I am not exactly a math genius right now.

Would greatly appreciate it!

Thank you greatly


Molecular mass of leupeptin is: +-426gram/mole (make the math yourself: take the mass of leupeptin with the H2SO4 (475.6 (Leupeptin × 1/2 H2SO4) and substract the mass/mole of 1/2 H2SO4 ==> it should be something like 475 - 98/2 .... give or take... check it)

And you allready have a stock solution.., so you simple use the 2mg/ml and the knowledge you have about the molecur mass.

You want 200µM = 200µmoles per liter....

And you know how much 1 moles is: 426 gram..

So how much gram do you need to have 200µmoles to add to 1 liter?

If you know how much that is... you can easly recalculate it for any volume...