Cleaning, Regeneration, and Storage of Chromatofocusing Columns

INTRODUCTION

Chromatofocusing separates proteins on the basis of differences in their isoelectric point (pI). A chromatofocusing column should be cleaned and regenerated after use, as described in this protocol, to remove any strongly bound substances. The following observations indicate that column cleaning may be necessary: increased back pressure in the column, a color change at the top of the column, loss of resolution, or reduced sample recovery. To avoid these problems, clean the column routinely (e.g., after every fifth or tenth run). More frequent and extended cleaning procedures may be necessary if complex samples are applied. The steps in this article are guidelines. Personal experience with possible contamination should be used to evaluate which cleaning method is suitable.