- Secondly, reactive oxygen species (ROS) emissions will also be evaluated on all skeletal muscle tissue samples. Briefly, a Fluorolog 3 (Horiba Jobin Yvon) spectrofluorometer with temperature control and continuous stirring will be used to monitor Amplex Red (Invitrogen) oxidation in freshly isolated mitochondrial suspensions obtained from the skeletal muscle biopsies. Amplex Red oxidation will be measured in the presence of glutamate (10 mmol/L), malate (2 mmol/L), and succinate (10 mmol/L). The fluorescent signal will be corrected for background auto-oxidation and calibrated to a standard curve. The H2O2 production rates will be expressed relative to mitochondrial protein.