A Raman Algorithm to Estimate Human Age From Protein Structural Variations in Autopsy Skin Samples: the Proteins’ Biological Clock
Abstract The recent increase of the number of unidentified cadavers has become a serious problem in the world. As a simple and objective method for age estimation, we attempted to utilize Raman spectrometry for forensic identification. Raman spectroscopy is an optical-based vibrational spectroscopic technique that provides detailed information about molecular composition and structure. Building upon our previous proof-of-concept study, Raman spectra of abdominal skin sample were measured in 132 autopsy cases and protein-folding intensity ratio (RPF) was calculated. There was a strong negative correlation between age and RPF with a Pearson correlation coefficient r = 0.878. The results of cross validation suggested that Model 2 (the square of RPF) is the best model with lowest mean squared error (127.9) and highest coefficient of determination (0.743) among the four models. Our results indicate that the there is a high correlation between the age and RPF. The Raman biological clock of protein folding can be used as a simple and objective forensic age estimation method of unidentified cadavers.