Developments of Methodology for Intracellular Oxygen Tension Based on Phosphorescence Lifetime Measurements of Ir(III) Complexes

Abstract

Oxygen concentration of living cells is one of the key parameters in various metabolic processes. Phosphorescence imaging techniques allow estimation of intracellular oxygen levels, because the intensity and lifetime of phosphorescence are significantly dependent on the concentration (partial pressure) of molecular oxygen. We herein demonstrate that the phosphorescence lifetime measurements using a microscope equipped with a time correlated single photon counting system or a gated intensified charge-coupled device camera and intracellular oxygen probes based on phosphorescent iridium(III) complexes are very useful for visualization of heterogeneous oxygen distribution in monolayer cultured cells.