Visualization of carrier ampholyte patterns in granular gel slabs. 2. Applications to preparative electrofocusing.

A topographic method for locating colorless proteins in focused Sephadex gel slabs is presented. The fluorescent isoelectric banding pattern of the carrier ampholyte (Servalyt) is utilized as a map to locate the proteins indirectly and non-destructively, and to guide their excision for preparative isolation. The method is illustrated with small-scale isolations of the major components of ovalbumin and human serum albumin, and with a scaled-up preparative isolation of the A and B components of beta-lactoglobulin. Fluorescence is used to localize accurately individual fractions of Servalyt in Sephadex slabs for preparative isolation. Isolated fractions were used to enrich selectively specific zones in the regular Servalyt mixture to increase the separation between close-lying proteins during focusing.