ABSTRACT
Objective To detect the molecular characteristics of the serum samples of rats suffered from sudden unexpected death of acute myocardial ischemia (experimental group) and death caused by air embolism (control group) applied by ATR-FTIR, and to discuss the forensic signiifcance of identiifcation of causes of death by sudden unexpected death of acute myocardial ischemia by two-dimension infrared spectroscopy. Methods Adult male SD rats were randomly divided into SCD group and DCAE group. The serum samples were analyzed by ATR-FTIR. The similarity coefifcient of spectra between two groups was analyzed by OMNIC software. The spectra with higher signal-noise ratio were obtained and used to build two-dimension spectra model by Matlab 2010a software. Results The peak shapes, positions and intensities of the spectra were extremely similar between two groups, and the similarity coefifcient reached 99.78%. Meanwhile, the similarity coefifcient of second derivative spectra decreased to 98.62% between two groups. Moreover, on the two-dimension spectra model, the component differences were present at about 1 625cm-1, 1 550cm-1, 1 080cm-1 and 860cm-1, and the number of auto-peaks was different, which suggested that the evident differences were related to the molecular contents of protein, glycogen, nuclear acid, and so on. Conclusion It is hard to differentiate the molecular differences of serum samples of rats between SCD and DACE based on one-dimension spectra. However, two-dimension infrared spectra could intuitively and effectively relfect the molecular differences, and it would apply to determining the cause of death in forensic science.