6. Development prospects

On a preparative and, a fortiori, industrial scale, chromatography has often largely taken precedence over electrophoresis for the purification of peptides and small proteins. The main reason for this is that most types of chromatography can be extrapolated to a large extent. Thus, techniques used on an analytical scale can be used for preparative purposes by increasing column dimensions. In the case of electrophoresis, on the other hand, simple extrapolation of analytical techniques does not allow us to go beyond the "micro-preparative" scale (a few milligrams in ten hours), while maintaining high resolution, due to problems inherent in the systems used. In most cases, electrophoresis is carried out in a flowing liquid. Various devices have been developed, whose operation is now relatively well mastered both theoretically and experimentally. They can be used to obtain quantities of the...