Optical Oxygen Microrespirometry as a Platform for Environmental Toxicology and Animal Model Studies

Abstract

We present a new methodology for testing physiological responses of small organisms (size 70-500 microm) via changes in their oxygen respiration monitored by quenched-phosphorescence oxygen sensing on a scale of a single organism. The method is demonstrated using three different formats of respirometric assays, Artemia salina and mouse embryos as model animals, and various effectors including compounds that induce and prevent superoxide-mediated and heavy metal ion toxicity. These assays, which employ soluble oxygen probes, standard fluorescent readers, and accessorytools, provide sensitive, noninvasive, real-time monitoring of animal respiration, and rapid assessment of EC50, sublethal effects, and metabolic alterations. Applications include screening for acute toxicity of compound libraries and environmental samples, and the study of animal physiology and metabolism.

Rapid High-Throughput Assessment of Aerobic Bacteria in Complex Samples by Fluorescence-Based Oxygen Respirometry

“…Real-time monitoring of samples is achieved by direct sensing of dissolved oxygen by fluorescence quenching using a soluble phosphorescent oxygen probe, a commercial reagent produced by Luxcel Biosciences. The probe, which has previously been validated with mammalian cells and small organisms (13,16), is stable, nontoxic, cell impermeable (4), and used in trace amounts by adding it to growth medium or directly to the samples in microwells. It provides contactless (i.e., noninvasive), real-time monitoring of bacterial oxygen respiration on a microscale in multiple samples in parallel.…”

“…Molecular oxygen is a key metabolite of aerobic cells and higher organisms, and alterations in cellular oxygen uptake serve as useful markers of their numbers, metabolic status, viability, and responses to various stimuli. The RST assays have been successfully applied to the monitoring of oxygen respiration of the yeast Saccharomyces pombe (16), mammalian cells (4), embryos, and whole organisms (13) and to study processes of apoptosis (15) and soil remediation (14).…”

Patterning, integration and characterisation of polymer optical oxygen sensors for microfluidic devices

“…6 Beyond cell-culture, oxygen consumption characteristics can further be used to determine the development status of higher organisms. For example, a direct link exists between oxygen consumption of pre-implantation mammalian embryos and their development status.…”

Micro-patterning of polymer-based optical oxygen sensors for lab-on-chip applications

“…As a key metabolite for aerobic cells, the lack of molecular oxygen in culture can ultimately lead to cell death. This makes changes in oxygen uptake of cells a powerful marker for their metabolic status, health and response to exogenous and endogenous stimuli [1]. In addition to single cell studies, oxygen consumption characteristics can further be used to determine the development status of higher organisms.…”