Sodium bisulfite composition - (Mar/09/2006 )

I would appreciate if all the methylation experts could suggest which sodium bisulfite to use for bisulfite treatment. The original S-8890 mentioned in all major protocols is no longer available.Instead we have S-9000 which the Sigma Aldrich catalogue describes as sod. metabisulfite which on dissolving in water converts to sod. bisulfite.If we use this do we treat it as sod. bisulfite/sod metabisulfite and make our stock solution accordingly? The other alternative is 243973 which is an exact replacement of the S-8890 and is also a mix of sod bisulfite and sodium metabisulfite . We already have S-9000 with us so I will be grateful for suggestions about it's exact usage in the original protocol for bisulfite conversion given by Frommer et al., 1992.
Thanks to all in advance !
S.S

in our hands, a super-saturated solution of bisulfite either sodium bisulfite or metabisulfite works fine.

7.6g in 18mLs of H20 to the appropriate pH is fine, there will be granules that won't dissolve and this is indicative of a super saturated solution.

I can't tell you the exact amount of NaOH required to pH need to look it up in the lab tomorrow.

Nick

Thanks Nick. I hope you can check the other details and let me know as we plan to start using the S-9000 soon.
S.S

Hi, methylink:

" a super-saturated solution of bisulfite either sodium bisulfite or metabisulfite works fine"

The " sodium bisulfite or metabisulfite " you said is 243973 or S9000?

Now, I donot know which one work.
I found that the percentage of (SO3) in 243973(66%) and S-8890 (59%) is different , so I donot know how to use 243973 to replace s-8890. Do you think I should increase the amount?

Thank a lot for your response.

kai