Time-dependent changes in the metal sites of metalloenzymes after initiation of a reaction by rapid mixing (see Rapid Scan Kinetics) may need to be monitored by techniques that require longer times for data acquisition (e.g., EPR or Mössbauer). Dr. Edmondson has significant experience in using the freeze-quench method in which mixed solutions are frozen (quenched) in milliseconds for leisurely spectroscopic investigation of time courses or chemical intermediates. The MRIL provides a state-of-the-art freeze-quench EPR or Mössbauer kinetics instrument as a satellite facility [Dale E. Edmondson, Emory].