Higher-accuracy method for measuring minichromosome stability in Saccharomyces cerevisiae.

The minichromosome maintenance assay is frequently used to characterize mutations genetically that affect the initiation of DNA replication or to decipher functional components in autonomously replicating sequences. The assay determines minichromosome loss by measuring the percentage of plasmid-containing cells in cultures after a period of growth in nonselective medium. Here we analyze data acquisition errors that contribute to the low accuracy of the routine versions of the assay. We propose modifications that eliminate errors in the acquisition of two variables and significantly improve the accuracy of the assay.