Q: Properties of Phospho-cellulose (P11, Whatman)

[Dima Klenchin]

Dear all,

I'm using P11 as a first step of protein purification. In a little
booklet that comes with it, the company puts some pretty scary notes
about it's use. Something like "precycle, use right away or store no more
than a week, and only in no less than 0.5 M phosphate". Sort of justification 
for it is alledged instability of ester linkage to the cellulose. 
My Q is: is this really truth? Does phosphocellulose really go bad over 
prolonged storage? I mean, it't kind of pain in the neck to precycle
it. Life would so much easier if  can store it in ready-to-use form for at least 
month. Can I simply add phosphate, azide and count on the same results with 
"old" stuff as with freshly prepared matrix? 

Folks experienced with phosphocellulose, please, send your comments.

Thanks in advance,

- Dima