[Histonet] (no subject)

[Kate Davoli]

I'm all set to DYI my own phosphomolybdic/phosphotungstic acid solution for
running a Masson Trichrome, but I see that the former reagent was
purchased as "phosphomolybdic acid hydrate".

All the recipes I have seen call for just "phosphomolybdic acid" but that
is not a reagent that appears to exist without the water molecules coming
along for the ride, unless you want to invest in chromatography grade
stuff, which I think histology folks probably don't routinely do.

The recipes all call for equal gram amounts of each of these crystals, so
here's my question:

Do I calculate how much weight the water is taking up and add more
phosphomolybdic acid crystals (to account for its tagalong water molecules)
than called for in the recipe?  Or are these recipes already assuming that
phosphomolybdic acid HYDRATE is the reagent you have on hand, and I should
stick with equal amounts?

This question is somewhat complicated by the fact that the molecular
formula on the bottle is listed as H3Mo12O40P.XH2O ... which I think means
the manufacturer won't bet on exactly how many water molecules are involved.

Any advice appreciated!

Katherine Davoli, BA, HTL(ASCP)CM
Supervisor & Lab Manager, Tissue Culture & Histology Core Module
Ophthalmic and Visual Sciences Research Center
Department of Ophthalmology, University of Pittsburgh
Mail Stop Code: EEI010901
930 Eye & Ear Institute, 203 Lothrop Street
Pittsburgh, PA 15213
(412) 647-8256    davolika at upmc.edu and kdavoli at gmail.com