In-Gel Detection of DNA: Application to Study of Viral DNA Metabolism by Use of Pulsed-Field Agarose Gel Electrophoresis

The introduction of pulsed-field agarose gel electrophoresis (PFGE) has expanded the list of particles separable by use of gel electrophoresis to include: (1) linear
DNA
s as long as 3–6 Mbp, (2) DNA- protein complexes and circular DNAs that become arrested during invariant field agarose gel electrophoresis; and (3) micron-sized spheres that also become arrested during invariant field agarose gel electrophoresis (reviewed in refs.
1
–
3
). During the replication, recombination and packaging of DNA by the various double-stranded DNA bacteriophages, circular DNAs, protein-DNA complexes, and end-to- end joined mature DNA multimers (concatemers) as long as 0.5–1.0 Mbp are formed (reviewed in refs.
4
,
5
). Thus, in addition to being useful for genome mapping (
1
,
2
,
6
,
7
and
see also
Chapter 18 ), PFGE also is useful for studying the DNA metabolism of both bacteriophages and, presumably, other viruses.