METHOD FOR PRE-FRACTIONATION OF COMPLEX SAMPLES

摘要

The present invention relates to a method for pre-fractionation of complex protein and/or peptide samples. The method comprises the following steps: a) loading the sample onto pre-packed media able to separate proteins/peptides according to their pI-value; b) eluting the media by centrifugal force under denaturing conditions with at least three buffers having different pH in a stepwise manner to obtain at least three fractions separated according to pI-value; and c) subjecting each fraction to further separation in a pH-range corresponding to the pI-values of said fractions. The invention also relates to a kit comprising at least one spin column or multiwell plate filled with chromatography medium able to separate proteins/peptides according to pI-value, at least three buffers, and one or more IPG strips having a narrow pH-range adapted to each of said buffers.