A microassay of O2 concentrations based on oxygen-induced chemiluminescence in anaerobic lipoxygenase reactions

The preparation of chemiluminescence probes for assaying O2 concentrations in microsamples is described. This probe is based on an anaerobic lipoxygenase-linoleate system continuously generating reactive intermediates which in a spontaneous reaction with added O2 yield an excited species. The resulting chemiluminescence signals are highly reproducible upon repeated sample application and unaffected by even large variations in the contents of lipoxygenase-1 and linoleic acid. The linear assay range is between 0.25 and 25 nmol of O2. The assay system described is stable for 90 +/- 10 min, irrespective of the number of samples added, and the probe can be regenerated thereafter by adding linoleic acid.