Preparation of sodium orthovanadate solutions

[admin]

Hi All
I'm in dire need of some advice on the preparation of a sodium orthovanadate solution used as a cell culture treatment to inhibit protein phosphotyrosine phosphatases. I've heard of two methods: making it up in water, pH10, boiling and then readjusting to pH10 to ensure presence of monomers as well as making it up fresh just before addition to cells. If anyone has any advice on the best method to use, I'd be very grateful.
Ciao

posted by micheline (please re-register thanks!)

[danfive]

I use sodium orthovanadate from Sigma (#S6508) and prepare it just as you described. Making a stock bottle of ultrapure water at pH10 is the most useful step. Boiling works very fast and if the chemical is fresh it may change its initial yellow color to clear once added to solution, just boil it for a few minutes to be sure all the decavanadate is converted. I freeze mine in epi-tubes and throw out any remaining solution after the first thawing, but preparing it fresh is probably the better technique.

[mickey07]

Thanks for your reply, Danfive. I have decided to make the vanadate up fresh everytime and boiling it for a few minutes before use. Thanks for the very useful tip!!!!
Cheers