Roel Nusse: Assessment of Hepatocyte Ploidy by Flow Cytometry

Polyploidy is a common and dynamic feature of mature rodent and human hepatocytes. While polyploidization occurs naturally during growth, alterations in the distribution of diploid and polyploid cells in the liver can be indicative of tissue stress or a pathologic state. Here, we describe a method for flow cytometric quantification of ploidy distribution by staining with propidium iodide. We first outline a hepatocyte isolation procedure from mouse liver through a two-step perfusion system for analysis of cellular ploidy. In an alternative approach, we employ a nuclei isolation protocol to assess nuclear ploidy. Finally, we describe how the use of fluorescent cell markers is compatible with these methods and helps retain information on cellular position within the tissue.