Measurement of Nucleoid Size Using STED Microscopy

Abstract

Mitochondria are equipped with their own DNA (mtDNA), which is packed into structures termed nucleoids. While nucleoids can be visualized in situ by fluorescence microscopy, the advent of super-resolution microscopy, and in particular of stimulated emission depletion (STED), has recently enabled the visualization of nucleoids at sub-diffraction resolution. Super-resolution microscopy has proved an invaluable tool for addressing fundamental questions in mitochondrial biology. In this chapter I describe how to achieve efficient labeling of mtDNA and how to quantify nucleoid diameter using an automated approach in fixed cultured cells by STED microscopy.