Maxicell

Maxicell is a system developed by Sancar et al. at 1978. Plasmids escape UV-induced damage because of their small size. A bacterium, which the host DNA is damaged by UV light irradiation continues to express plasmid genes. While transcription of host-DNA is inhibited, multiple copies of an inserted plasmid continue to be expressed. The plasmid will replicate and transcribe gene products. The method was used for amplification of photolyase in Escherichia coli.