Effective spin probe for the EPR imaging and in vivo detection of intracellular ROS (superoxide, peroxynitrite etc.). ACP can be easily protected with esterase to yield cyclic hydroxylamine, which can be oxidized by reactive oxygen species to yield ESR-detectable nitroxide radicals. The nitroxide radical is resistant to reduction by vitamin C and thiols.

Half-life time of nitroxide radical in biological environment up to 4h.

Samples in frozen condition (-80 °C or liquid nitrogen) can be stored up to 6 months.