Oxygen flux - instrumental background

high-resolution terminology - matching measurements at high-resolution

Oxygen flux - instrumental background

Description

Instrumental background oxygen flux, J°_O2, in a respirometer is due to oxygen consumption by the POS, and oxygen diffusion into or out of the aqueous medium in the O2k-Chamber. It is a property of the instrumental system, measured in the range of experimental oxygen levels by a standardized instrumental background test. The oxygen regime from air saturation towards zero oxygen is applied generally in experiments with isolated mitochondria and intact or permeabilized cells. To overcome oxygen diffusion limitation in permeabilized fibres and homogenates, an elevated oxygen regime is applied, requiring instrumental background test in the same range of elevated oxygen.

Instrumental background correction eliminates errors by systemic flux compensation, automatically performed by DatLab.

Automatic correction for the instrumental background oxygen flux is an essential standard in high resolution respirometry. At the same time an instrumental background experiment is the ultimate test for instrumental performance, evaluating chamber performance after completion of all elements of the Sensor test. The instrumental background oxygen flux measured at air saturation should reflect the theoretically predicted volume-specific oxygen consumption by the oxygen sensor. The actual agreement using experimental respiration medium provides at the same time a test that excludes microbial contamination of the medium or serves to evaluate any autoxidation processes in newly tested experimental media.

Abbreviation: J°_O2

Reference: MiPNet14.06; Gnaiger_2008_POS; Gnaiger_2001_RespPhysiol

MitoPedia methods: Respirometry 

• See MiPNet14.06 InstrumentalO2Background for experimental details of the instrumental background test, and for downloading the Excel template for analyzing instrumental background experiments.
• Compare Chemical background correction of oxygen flux.