Cell survival as studied by electron paramagnetic resonance

Abstract Conditions influencing the EPR spectrum of frozen rat liver tissue have been studied. The free radical concentration decays with time. This process is thermally activated with an activation energy of 0.4 eV. The nonheme iron complexes at g = 1.940 are dependent on the anaerobic conditions producing an increase of the signal when stored in nitrogen atmosphere at room temperature as compared to the sample stored in air.