sodium bisulphite vs. metabisulphite - (Oct/24/2005 )

Has anyone seen any difference between these chemicals in bisulfite conversion? Also, it seems most protocols use higher concenrations of bisulphite vs. metabisulphite in their assays, it there a standard conversion factor one should use?

There is no much difference between them in terms of converting ability.
Sodium metabisulfite dissolves to form two HSO3 ions such that 2.5M metabisulfite is equivalent to 5M bisulfite. So lower molar concentration of metabisulfite is used in DNA modification and metabisulfite is easier to dissolve than bisulfite.

Thanks a bunch, makes sense.