Help!! w/Particle Purification and Resolution

[mkrol]

Hey there Happy Virologists!!
I have a practical lab problem that i'd like your collective input on.

My difficulty is that I would like to somehow resolve a mixture of virus
like particles I have, with diameters ganging from 28 nm to 20 nm.  There
seem to be discreet populations as i do see what seems to be a couple of
overlapping peaks on a sucrose gradient.  The S value of these things is
somewhat less than 88S, but i'm not exactly sure, as i don't presently have
access to an analytical ultracentrifuge.  I may have access to one in a
month or two, but i am unfamiliar with them and their uses/properties. My
particles, while fairly stable, are unstable enough that i don't want to
try equilibrium centrifugation...i think the high [salt] will make them
fall apart, and i actually want to resolve by size if possible, rather than
density. 

How MIGHT i resolve different size things in this size range?

Any and all suggestions would be appreciated, no matter how crazy they may
seem.

Many thanks!!


-Micky Krol
Graduate-Student-at-large
Institute for Molecular Virology
University of Wisconsin-Madison

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