Abstract: An operation instrument for the examination of an object, for example a biopsy needle, a catheter, or a radioactive capsule intended for radiotherapy. The instrument comprises an active component which is adapted to be detected with a nuclear magnetic resonance method, such as magnetic imaging, in such a way that the active component contains a marker which carries NMR-active nuclei and, in interaction with the marker, an enhancer which causes the enhancement of an NMR signal by means of dynamic nuclear polarization as a result of saturating the electron spin system of the enhancer which causes the enhancement of an NMR signal by means of dynamic nuclear polarization as a result of saturating the electron spin system of the enhancer with an external energy, so-called saturation energy. The operation instrument comprises a marker container and a transfer linen for transferring the saturation energy into the enhancer.