Real-Time Monitoring of Hydrogen Peroxide Levels in Yeast and Mammalian Cells

Hydrogen peroxide (H₂O₂) is an important signaling molecule involved in regulating antioxidative transcriptional responses, cellular differentiation, and hypoxia response. H₂O₂ generation and signaling are highly localized processes. Understanding the dynamics of this molecule inside intact cells with subcompartmental resolution is instrumental to unravel its role in cellular signaling. Different genetically encoded fluorescent sensors have been developed over the last few years that enable such non-disruptive monitoring with high spatiotemporal resolution. In this chapter, we describe the use of these genetically encoded sensors to directly monitor H₂O₂ dynamics in yeast and cultured mammalian cells.