Estimating the chance of success of archaeometric analyses of bone: UV-induced bone fluorescence compared to histological screening

For most archaeometric analyses on archaeological bone material, such as the determination of the isotopic composition or genetic approaches, an advanced degree of diagenetic alteration can make designated analysis impossible. Since the lack of a positive signal is mostly seen only after time consuming and cost intensive sample processing, the need for an easy-to-apply screening method that allows a pre-selection of samples containing well-preserved biomolecules is obvious. In this study, we visually determined the UV-induced autofluorescence of 76 horse bone cross-sections, all from prehistoric archaeological sites of varying environmental and chronological background. In order to assess the screening potential of this method, the macroscopic fluorescence appearance of each sample was compared to its degree of histological preservation, a feature which is also commonly utilised as a marker for overall biomolecular preservation in bone. Collagen content and quality as well as PCR-success for DNA analysis were determined and evaluated with regard to the positive/negative predictive value of UV fluorescence and histological screening. The aim was to create a screening method designed not only for daily laboratory practice, but also for archaeologists with no access to elaborate machinery and who need to pre-select the most promising samples to send out to a contractor for archaeometric analyses. ► We compare bone fluorescence to histological screening to assess overall preservation. ► Evaluating bone fluorescence increases the chance to choose well preserved specimens. ► We suggest using this method to identify samples most promising for further analyses. ► Fluorescence screening is slightly more effective than histological screening.