Endogenous Fluorescence Analysis: Preliminary Study Revealing the Potential of this Non‐invasive Method to Study Mummified Samples

Abstract

Autofluorescence analysis allows new insights on human tissue without any dye in a non-invasive way and therefore seems well suited to study historical samples. An optical set-up recorded emitted autofluorescence in 1/spectral and 2/lifetime domains from different samples' regions of interest. The studied samples were a mummified right hand, bog body (Tollund Man) feet and a male Caucasian hand (control sample). Spectral analysis revealed that mummified hand exhibited broad autofluorescence spectra, whereas Tollund Man's feet exhibited a weak single peak with 405-nm excitation wavelength. Control sample spectra are weaker than that of the mummified hand but higher than the Tollund Man's feet. Lifetime measurements indicated the presence of classical endogenous fluorophores on the mummified right hand. The Tollund Man's feet exhibited two patterns of lifetime measurements: healthy zone exhibited lifetime values at four emission wavelengths but skin lesions at only two wavelengths. This first report of mummified samples' autofluorescence analysis suggests the potential of optical analysis for archeologic research.

Bogged Down

“…In contrast to the previously mentioned methods, which can be applied to both osteological and soft tissue specimens, most of the medical imaging techniques in this discussion are relevant exclusively to soft tissues (Zanello et al 2017). In other bioarchaeological contexts, medical imaging may be employed even when only bone is present (Villa & Lynnerup 2012).…”

“…CT scans are similar, except they take more detailed cross-sectional images of the body that are combined using computer software (Zanello et al 2017). MRI is the most detailed imaging process of the three discussed here, which creates images of organs and tissues such as tumours.…”

“…Zanello and colleagues (2017) successfully utilized another imaging technique called endogenous fluorescence for non-invasive means of examining remains, including bog bodies. This process employs a laser to stimulate fluorescent particles naturally present within soft tissue, causing them to emit light from areas where they absorb the laser's energy (Zanello et al 2017). Additionally, this method can differentiate between healthy tissue and tissue containing abnormalities such as warts, as observed on the feet of Tollund Man.…”

“…There has been minimal medical imaging performed on Tollund Man, likely due to his autopsy in 1950 (Zanello et al 2017). In recent years, he underwent examination using endogenous fluorescence.…”

Diet and Radiocarbon Dating of Tollund Man: New Analyses of an Iron Age Bog Body from Denmark

“…From the time of his discovery, Tollund Man has attracted much scientific interest. Through the years he has therefore been subjected to a number of forensic and scientific investigations seeking to unravel the secrets of his death (which presumably was part of a ritual sacrifice) and to uncover as much as possible about his life and health and thereby also the living conditions of Iron Age people in general (Helbaek 1950;Fischer 2012;Zanello et al 2017;Nielsen 2017, Nielsen 2018. This article presents the results of the newest investigations regarding his diet and date.…”