Detection of myosin light chain 1 from a forensic biological material to identify human striated muscle

In forensic practice, it may be necessary to identify the source of the tissue at crime scenes and elsewhere. We examined the physiological presence of myosin light chain 1 (MLC1), a structural protein in striated muscle, and designed a method that can identify human skeletal muscle from tissue fragments with very small sample consumption by quantitative analysis of MLC1. The MLC1 content in human muscles was compared with that in 13 different animal muscles and human organs, excluding horse muscles. The mean MLC1 content in the investigated iliopsoas muscles was 0.89 mg/g wet weight. For species identification, it is possible to differentiate human muscles from the muscles of other animal species except for horse. The MLC1 content in various human organs is very low, and differentiation between muscles and other organs is easy. The results showed that this method is highly sensitive, has good organ and species specificity, and is thought to be useful for the preliminary analysis of tissue fragments.