Dealing with minor differences in bone matrix: can spectra follow the DNA preservation?

Abstract

ABSTRACT Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy is a relatively fast and inexpensive but reliable method that can be used as a rough screening tool for DNA preservation. Although it is an excellent analytical tool, it only provides relative information on the chemical structure of heterogeneous materials such as bone and its usefulness and accuracy for predicting the preservation of DNA in samples originating from different body regions of minimally altered remains was never tested before. 144 bone samples were collected from different body regions of three individuals discovered in a Second World War mass grave. DNA was extracted and quantified, followed by STR typing. Samples were analysed with ATR-FTIR spectroscopy. Comparing the preservation state of DNA and chemometric indices, the usefulness of the method was tested. Correlations between the DNA preservation and chemometric indices were highly variable, especially when considering different body regions. Best DNA preservation was correlated with a balanced ratio between carbonates and phosphates, and with high collagen quality and quantity. It seems that, when dealing with relatively young and well-preserved remains, more attention should be paid to collagen quality. In addition, the results indicate that DNA quality and DNA quantity correlate differently with chemometric indices.