A Tool for Measuring Oxygen via Phosphorescence

Accurate measurements of dissolved O2 as a function of time have numerous biological and chemical applications. Detection of O2 using a Pd phosphor complex is based on the principle that the phosphorescence of this probe is inversely related to dissolved [O2]. Biologic samples are flashed with red light using special instrumentation that captures emitted light and a customized software program that determines [O2] as function of time. O2 concentration is calculated by fitting the decay of the phosphorescence to an exponential curve. Twelve tasks were identified, which allow full control and customization of the data acquisition, storage and analysis. The program used Microsoft Visual Basic 6 (VB6), Microsoft Access Database 2007, and a Universal Library component that allowed direct reading from the PCI-DAS 4020/12 I/O Board. A relational database was designed to store experiments, pulses and pulse metadata, including phosphorescence decay rates. This combination of experimental setup and software program can be used on wide range of experiments. The tool has now been used to conduct over 2,000 experiments during the last two years, as it permits reliable measurements of cellular O2 consumption over several hours.