Non-Toxic Mutagenesis in Bacteria
1) Useful for mutating recombinant DNA phage clones and/or libraries using multiple rounds of growth and selection of viable phage
2) Bacterial cells can be grown under selective conditions when screening for phenotypes with an increased or decreased quantitative index. Used during growth appears to create changes in morphology.
Background: VivoSyn® can
be used in bacterial culture media to increase the natural mutation rate by
inhibiting DNA repair mechanisms. The natural mutation rate is increased ~200
fold above background. While this level of mutation rate does not interfere with
plasmid production during routine amplification, continued serial dilution
results in the significant accumulation of mutations. After two to three
cycles the the number of mutations start to be significant. At the
same time the viability of bacteria or phage will start to drop as
they accumulate deleterious mutations.
Method works great with phage systems as viable phage can be harvested after infection and used to immediately infect another culture of bacteria without purifying DNA and plating cells. Using M13 recombinant phage mutations rates were ~1 to two mutations per insert. Provides and easy and low cost method to mutate entire collections of cloned DNA or cDNA phage libraries.
To isolate new strains bacterial cells can be grown under selective conditions for continuous traits. This type of approach is not suitable for discontinuous traits where a period in the absence of selection is needed for the expression of the genes leading to the new phenotype. This is great non-toxic mutagenesis tool.