5M NaF won't dissolve! - (Nov/04/2009 )

So i have to make a solution of 5M NaF to use in a lysing reagent for HEK293T. Problem is that I cannot get NaF to dissolve completely. Any suggestions? Thanks.

Solubility: 4 g/100 ml water @ 15C (59F)
Molecular Weight: 41.99
( http://www.jtbaker.com/msds/englishhtml/s3722.htm )

Depends on the lysing reagens because in water maybe a little more than 0.1 M

4.3g/100ml at 25C (merck index). ~1M. not soluble to 5M.

Thank you for the info!

When you do try to dissolve it, how far away from completion do you get? Try dissolving it at higher temperatures than 15C or 25C.

swanny on Nov 4 2009, 07:55 PM said:

according to the merck index, sodium fluoride is soluble to 5gm/100ml at 100C. not much more than at 25C. also, you will end up with a supersaturated solution (if it remains in solution) when it cools to room temperature.

I have tried prepared 1M NaF. I do not encounter any problem at all. It dissolved very quickly (within 3 minutes) at room temperature.

I agree, reduce the stock concentration of 5M. to between 0.5M and 1M. I was using 0.5M, for a stock of 10X for lysis buffer, and it dissolved quickly in water.

amelia417 on Sun Nov 15 22:59:51 2009 said:

Hi - do you keep the stock at room temperature or in the -20 for the lysis buffer?

Thanks

high salt solution keeps for a while non-contaminated but better with NaN3 at RT