Assessment of Beta Cell Viability

This unit contains detailed protocols for the simultaneous identification of the human pancreatic β cells and determination of their viability by flow cytometry. The enumeration of β cells is based on the ability of the cell-permeable form of the zinc-selective dye, FluoZin-3-AM, to bind intracellular labile zinc stored at higher levels in these cells than any other types of cells in the body. Although staining of intracellular labile zinc by FluoZin-3-AM is dependent on the metabolic activity of β cells, co-staining with a mitochondrial transmembrane potential indicator allows the accurate determination of viability. Simultaneous measurement of intracellular antioxidant thiols is also compatible with the detection of β cells containing metabolically active mitochondria. The method for assessing the mitochondrial functionality by flow cytometry described herein is simple to perform and sufficient to detect the viability of β cells in human islet preparations.