A new article in Current Biology highlights a method for tracking DNA mutations in real time. The key to this approach is using a fluorescent-labeled derivative of MutL, a protein involved in DNA mismatch repair. The accumulation of this fluorescent protein signals the occurrence of a mutation in a population of replicating E. coli bacteria. Even more significantly, this method allows the visualization of mutations that do not result in recognizable phenotypes. That means that it could be used to alert researchers to DNA errors they are not even looking for.

The video below shows 180 minutes of E.coli growth compressed to 12 seconds: