Protein Purification using isoelectric focusing with zwitterionic membranes

L. Ericsson (ericsson@u.washington.edu)
Sat, 17 Jan 1998 10:05:05 -0800 (PST)

At a recent conference this year Pier Giorgio Righetti described his
immobilized pH gradients (IPG) apparatus with zwitterionic membranes
creating "isoelectric traps" for individual proteins thus allowing for
continuous purification of proteins on a pilot plant scale basis. The
apparatus is described in an article in Anal. Biochem. Vol.247 pg1-10
(1997).

With this apparatus one can realize the advantages of isoelectric focusing
without the problems involved with separating the protein from acrylamide
or ampholytes.

Several similar apparatuses (Rotofor, Elphor, etc) to the Righetti
apparatus sold by Pharmacia-Hoefer have been on the market the last few
years but I seldom see a publication in which these instruments have been
used. What experience have the ABRFers had with these instruments? They
appear to be just the thing for purification of proteins for NMR, x-Ray,
and MS studies. No acrylamide or ampholytes to worry about, or is their a
problem?

-Lowell H. Ericsson, Dept. of Biochem., U. of Washington, Seattle, WA