ABSTRACT
Essentially, by employing pulses of voltage from different directions and durations, very much larger DNA molecules can be resolved than when using conventional, constant field gels. In pulsed field gels, these molecules are retarded and can be resolved from each other. The development of pulsed field gels has enabled substantial progress to be made in the sphere of genome mapping. In practice it has been found necessary to use changes in field direction to provide the requirement for a pulsating electric field as this has been shown to give the most effective separations. Note that at the heart of all pulsed field applications the gel itself is a conventional low-percentage nondenaturing agarose gel formed using conventional buffers such as TBE. In practice pulses can vary from 5 to 1000 sec, at field strengths from 2 to 10 V cm.
