Proteolytic changes in the muscles of cadaver are demonstrable by putrefaction experiment with the electrofocusing on polyacrylamide gels. These changes can--within a narrow limit--be used in the determination of time of death at a stage when the early signs of death are not suitable any more. A fraction with a pI-value of 7.2 appears as a proteolytic fission at 30 degrees C not earlier than the second day after death. This fraction can be detected at 20 degrees C from the fifth to the sixth day p.m. At 10 degrees C it will not be detectable until the ninth day p.m. At a pH-range between 6.9 and 7.7, at 30 degrees C and 8 days after death, or at 20 degrees C and 9 days after death, only a relatively stable fraction is detectable with a pI-value between 6.9 and 7.0.