Measuring Mutation Rates Using the Luria-Delbrück Fluctuation Assay.

The Luria-Delbrück fluctuation assay is one of the most commonly used methods for measuring the mutation rate in microorganisms. Specifically, it is used to measure the mutation rate at a particular locus or loci at which mutations give rise to a selectable phenotype. Here, I outline the essential features of performing Luria-Delbrück fluctuation assays as well as common missteps and tips for improving the accuracy of mutation rate estimates. In addition, I provide tools for analyzing data from fluctuation assays. This 96-well plate protocol has been optimized for use in yeast but should perform equally well for a range of microorganisms using standard microbiological methods.