When the technique of pulsed-field gel electrophoresis (PFGE) was first described by David C. Schwartz and Charles R. Cantor almost a decade ago (Cell, 37:67-75, 1984), many molecular biologists recognized its potential immediately. A flurry of innovation in instrumentation based on the idea followed in the next half-dozen years. Despite this interest and activity, only in the past few years has PFGE secured its place as a mature, integral laboratory tool in molecular genetics generally and the Human Genome Project particularly.
What Schwartz and Cantor demonstrated in 1984 was that, by alternately applying two electric fields at an angle across the gel instead of using one constant field, larger DNA could be resolved than ever before--much larger. With conventional electrophoresis in a constant field, DNA fragments above a certain size co-migrate in a broad band and do not separate properly.
"The key advantage to PFGE is that you can separate ...
