• Create Account

# What concentration and how much should I add? (Leupeptin)

### #1 Biochem_newbie

Biochem_newbie

member

• Active Members
• 25 posts
0
Neutral

Posted 10 March 2011 - 12:36 PM

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

http://www.roche-app...rt/1017101a.pdf

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

Would greatly appreciate it!

Thank you greatly

Edited by Biochem_newbie, 10 March 2011 - 12:38 PM.

### #2 pito

pito

Veteran

• Active Members
• 1,022 posts
51
Excellent

Posted 10 March 2011 - 01:17 PM

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...
If you don't know it, then ask it! Better to ask and look foolish to some then not ask and stay stupid.