Relationship between Myofibril Fragmentation Index and Postmortem Interval
SHEN LI1, YUAN RUI-ZHONG2, BIAN JIE3, HE MENG4, ZHAO ZI-QIN4
（1. Institute of Forensic Science, Yinchuan Public Security Bureau, Yinchuan 750001, China; 2. Department of Criminal Investigation, Chongming Public Security Bureau, Shanghai 202150, China; 3. Shanghai University of Medicine & Health Sciences, Shanghai 201318, China; 4. Department of Forensic Medicine, Shanghai Medical College, Fudan University, Shanghai 200032, China）
Objective To study the relationship between myofibril fragmentation index （MFI） of human skeletal muscle and postmortem interval （PMI）. Methods The protein concentrations of human right biceps brachii muscle and right quadriceps femoris muscle were obtained at different PMI, and detected at room temperature by biuret method. The MFI of skeletal muscle at 540 nm was measured by ultraviolet spectrophotometer. Regression analysis was performed with time of death as independent variable （x） and MFI as dependent variable （y）. Results In early PMI, the MFI of human skeletal muscle increased obviously according to the prolongation of PMI, and peaking by 12 h and then tended to steady. Within 12 h after death, the regression equations of right biceps brachii muscle and right quadriceps femoris muscle were y=32.660+3.227 x（r=0.987 9） and y=32.380+3.495 x（r=0.983 9）, respectively. Conclusion There’s high correlation between MFI and PMI. Combining with forensic practice, MFI can be used for the estimation of early PMI （especially in 12 h）.