# Drug dilution - (Jan/11/2012 )

Hi there

I am trying to figure out how to dilute a stock solution of my drug, Bafilomycin A1.

The stock solution is 100 uM and the desired concentration that I want to treat my cells is 200 nM.

Usually I deal with micromolar units and not nanomolar so I am a bit confused as to how to get to this final concentration.

Any arbitrary volume in calculations is fine. I would like to know the concept of how to get to such a low final preparing concentration.

The molecular weight is 622.83.

If anyone could help me with this calculation, I would greatly appreciate it.

Thank you,

Seems straightforward.....if you were to take 622.83 g and dilute into 1L you would have 1M, so for 100uM, you need 62.283 mg/L. Based on this site:

http://www.fermentek.co.il/bafilomycin_A1.htm

the compound is soluble at 5mg/mL in DMSO or methanol, so you probably don't need to make your 500X stock directly. You can probably make a 50,000X stock and then dilute it 1:100 if you really want a 500X stock solution.

1 nm = 1/1000th of a um. So 100 um = 100,000 nm.

Use C1V1=C2V2, making sure to keep the units the same (i.e. work in um or nm, not both).

Try this website, to help with conversions

http://www.graphpad.com/quickcalcs/Molarityform.cfm

Biochem_newbie on Wed Jan 11 17:23:59 2012 said:

Hi there

I am trying to figure out how to dilute a stock solution of my drug, Bafilomycin A1.

The stock solution is 100 uM and the desired concentration that I want to treat my cells is 200 nM.

Usually I deal with micromolar units and not nanomolar so I am a bit confused as to how to get to this final concentration.

Any arbitrary volume in calculations is fine. I would like to know the concept of how to get to such a low final preparing concentration.

The molecular weight is 622.83.

If anyone could help me with this calculation, I would greatly appreciate it.

Thank you,

Dear Biochem_Newbie,

As usual bob1 is absolutely correct...I just want to flesh it out a little

Your stock solution is 100uM........you want 200nm as your working concentration.

Easy ..........1uM = 1000nm

100uM = 100,000nM

Therefore your stock solution (100uM) needs to be diluted by a factor of 1:500.....to give 200nM

i.e. 1ul of stock to 499ul of media

10ul of stock to 4.99mls of media.......and so on

I have to say that these sorts of issues are very common place for all newbies in the lab........the more you do it the easier it will become.

Enjoy!!!!!

Kindest regards

Uncle Rhombus