Stock solution - (Feb/22/2016 )

I have to make the stock solution of powdered chemokines. I need to know what volume you need to resuspend the powdered chemokines for a 1000X stock.

For example one of the chemokines has a concentration of 20ug/ml, how would i make a 1000x stock?

Thanks!

1000x refers to the stock concentration respect to the concentration in the working solution, ie 1000 times higher concentration. If the final concentration of the chemokines you need is 20ug/mL, 1000x would be 20,000 ug/mL or 20 mg/mL

So how would i know how much volume to add to the powdered chemokine?

Im confused because the chemokine website I bought it from says "20ug". I was told to make a 1000x stock solution of that and know what volume to add. For my assay, I need to use 1000ng/ml concentration which i would use from my stock solution once I have it made. 

But making the stock solution is throwing me off. 

Correctme if I'm wrong:

your source chemokine (bought) = 20ug/mL

stock concentration desired = 1000x

working concentration (final) = 1000ng/mL

So your desired stock concentration would be 1000 ng/mL x 1000 = 1000000ng/ mL = 1 mg/mL stock = 1 ug/ uL

If the chemokine you bought is 20ug/mL you cannot make a stock of 1 mg/mL because your source is already 500 times more diluted. Are you sure about the units?