Practical use of chemical probes for reactive oxygen species produced in biological systems by γ-irradiation

Application of chemical probes, for detection of reactive oxygen species (ROS), was tested during γ-irradiation. The ethanol/α-(4-pyridyl-1-oxide)-N-tert-butylnitrone (4-POBN) and 3,3′-diaminobenzidine (DAB) were structurally stable enough to detect ^{{radical dot}}OH and H₂O₂, increasingly generated by γ-irradiation up to 1000 Gy. Interestingly, the production rate of H₂O₂, but not ^{{radical dot}}OH, during γ-irradiation, was significantly different between in vitro systems of lettuce and spinach. These results suggest that 4-POBN and DAB could be utilized as a semi-quantitative probe to quantify ^{{radical dot}}OH and H₂O₂, produced by γ-irradiation up to 1000 Gy.