In Vitro: 3-MeOARh-NTR (10 μM, 30 min; cell incubated with 20% O2 and 10% O2 for 12 h) produces a strong fluorescence signal in living HeLa cells with decreasing oxygen contents. 3-MeOARh-NTR (10 μM, 30 min) produces fluorescence imaging of kidney tissues from mice with λex = 488 nm and λem=510-590 nm. Thus, 3-MeOARh-NTR is a efficient probe to evaluate kidney hypoxia by NTR detection.