Elvio,
I have had very good results with proteins on Poros R2 in the past, but there
are a few precautions one must take because of the fragile nature of the
particles. First, it is very important to remove fines by repeately suspending
the particles in solvent (IPA or methanol have worked) and allowing the
particles to settle for a while. Then remove the still-cloudy top liquid. Do
this at least 3X. Otherwise the fines will clog the frit and increase back
pressure. Second, when packing, be very gentle stiring with a spin bar so as not
to fracture particles. I usually give the slurry a brief spin then turn it off
until the packing rate gets very slow. Then another brief spin. I and others
have noticed that when packing multiple columns from the same Poros slurry, the
packing times get longer and longer, probably because of accumulation of broken
particles. The slurry is always made fresh for each packing session. A 75um ID
X 10cm bed height Poros 10R2 column should be able to operate at 4-600nL/min at
no more than 3-400psi. Hope this helps.
Dan Kirby
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