Genome size determination using flow cytometry of propidium iodide-stained nuclei.

With the rapid expansion of whole-genome sequencing and other genomic studies in nonmodel -organisms, there is a growing demand for robust and user-friendly methods for estimating eukaryotic genome sizes across a broad range of taxa. Propidium iodide (PI) staining with flow cytometry is a powerful method for genome sizing because it is relatively fast, works with a wide variety of materials, and provides information on a very large number of nuclei. In this method, nuclei are stained with PI, which intercalates into the major groove of DNA. Unknown samples are typically costained with standard nuclei of a known genome size, and the relative fluorescence is used to calculate the genome size of the unknown.