“…Half a century of continuous progress in nitroxide chemistry has resulted in the design of specific NRs for spin labeling (Berliner, 1998), sitedirected spin labeling (Hubbell et al, 2000), EPR oximetry (Halpern et al, 1994;Swartz, 2004), pH (Khramtsov et al, 1982, thiols (Khramtsov et al, 1989(Khramtsov et al, , 1997, redox (Swartz et al, 2007) and NO measurements (Akaike et al, 1993;Joseph et al, 1993;Woldman et al, 1994). Over the past decade low-field L-band (1.2 GHz) EPR spectrometers and imagers have become commercially available allowing for functional EPR measurements in isolated organs (Komarov et al, 2012) and small animals such as mice Bobko et al, 2012).…”