Improved method for EPR detection of DEPMPO-superoxide radicals by liquid nitrogen freezing.
5-diethoxyphosphoryl-5-methyl-1-pyrroline N-oxide (DEPMPO) is frequently used as a spin trap for the measurement of superoxide by EPR spectrometry. However, its half life is fairly short in room temperature. We here show that superoxide radicals trapped by DEPMPO can be successfully recorded at -196 degrees C. Moreover, we show that the signal intensity remains unaltered for up to 7 days, when the samples are stored in liquid nitrogen. Our new approach for measurement of superoxide should greatly simplify the studies of this important radical in biological systems.
Dambrova
M
M
Department of Medicinal Chemistry, Latvian Institute of Organic Synthesis, Aizkraukles St. 21, Riga, LV-1006, Latvia. dambrova@biomed.lu.lv
Baumane
L
L
Kalvinsh
I
I
Wikberg
J E
JE
D000818:Animals; D002417:Cattle; D003497:Cyclic N-Oxides / Q000032:analysis*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005615:Freezing; D006207:Half-Life; D007700:Kinetics; D009584:Nitrogen / Q000378:metabolism*; D012996:Solutions; D013113:Spin Labels; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000032:analysis*; D019820:Xanthine / Q000378:metabolism; D014969:Xanthine Oxidase / Q000378:metabolism
D003497:Cyclic N-Oxides; D012996:Solutions; D013113:Spin Labels; D013481:Superoxides; C098505:5-diethoxyphosphoryl-5-methyl-1-pyrroline N-oxide; D019820:Xanthine; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase; D009584:Nitrogen