Immobilized pH gradients and preparative isoelectric focusing

In 1992, immobilized ph gradients (IPGs) were introduced, resulting in an increase in resolution by one order of magnitude compared with conventional isoelectric focusing (IEF) [1, 2]. By 1980, it was apparent to many IEF users that there were some inherent problems with the technique, which had not been corrected in more than 20 years of practice and were not likely to be solved