Separation and Size Determination of DNA over a 10-,200 kbp Range.

Some types of pulsed-field gel electrophoresis (PFGE), including CHEF (contour-clamped homogeneous electric field), give straight lanes and excellent separations of a wide range of DNA sizes on one gel (ref. 1 and Chapters 1 , 2 , 5 - 7 ). Here conditions are described for the separation of DNA in the l0-,200-kbp size range by CHEF. CHEF resolution in this range exceeds that of many commonly used size standards. Production and use of a size standard giving a 10-kbp ladder in the l0-,200-kbp range (2) is described and examples of separations are shown.