Novel 19F MR probe with the ability of creation of a depot in the living system is presented. This agent is pH- and termoresponsible with the phase transition point from liquid into the solid state at the temperature above 20 ºC. The MR properties were assessed by relaxometry and 19F spectroscopy/imaging. In vivo application confirmed efficiency of depot visualization; strong 19F MR signal was detected in all animals. No adverse effects of the probe to the animals were observed. Sufficient MR sensitivity of the probe and its slow degradation in animals suggest potential for a theranostic use.