PREPARATIVE-SCALE PURIFICATION OF DNA RESTRICTION FRAGMENTS BY CONTINUOUS-FLOW GEL-ELECTROPHORESIS

A method is described for large-scale (10-100 mu g) purification of in dividual DNA fragment lengths from a mixture of fragment lengths using a continuous-flow, toroidal gel electrophoresis system that is commer cially available. Preparative-scale separations of fragments up to app roximately 1000 bp differing in length by as little as 100 bp are obta ined. Typical recoveries of purified DNA fragments range from 25% to 4 0% of starting material.