Remote Archaeobiological Microscopy

An update from Rachel Kalisher, PhD Student, Joukowsky Institute for Archaeology and the Ancient World

For the first time in nine years, I was not in the field excavating this summer. Instead, I was working under the guidance of Andrew Scherer on a proctorship focusing on Remote Archaeobiological Microscopy, which included adapting bench microscope spaces to environments best suited for remote work, as well as continuing to develop methodologies for capturing various types of images for different biological tissues.

Three microscopes were setup on Rhode Island Hall’s Mezzanine; two polarizing microscopes were placed in the larger half of the space and one stereoscopic microscope was placed on the smaller half. The supply station and microscopes were in common spaces, while individual workspaces were cordoned off for individual researchers to store supplies and materials without needing to touch or contaminate other work benches.

Initial laboratory setup on RI Hall Mezzanine with designated common and individual spaces. Polarizing microscope bench on left, stereoscopic microscope bench on right.

Once setup was complete, I had two objectives for the proctorship. The first was to image a bone cast under stereoscopic light for an ongoing investigation into an archaeological trephination. The other was to image bone thin sections in polarizing light to observe cellular structures for my ScM in the Open Graduate Education Program.

The bone cast is of a skull trephination from Megiddo, Israel. I am preparing this Late Bronze Age case study for publication, and in doing so needed to investigate the trephination at the microscopic level. Understanding the way that the cuts were made, including patterning and whether they were done with a metal or stone implement, will be important pieces of information for my bioarchaeological reconstruction of the events. For this task I used a Leica EZ4D stereoscopic microscope, which has several lighting settings that illuminate the different topographies of the cast’s surface.

Observing the trephination cast with the Leica microscope.

My second goal was achieved using the polarizing microscope, a Nikon Labophot, which produced beautiful images of the cells in the spongy bone of a macaque vertebra. I had previously prepared these vertebral bone samples as thin sections at the Histology and Correlative Microscopy Center at NYU. Part of my ongoing ScM work in Ecology and Evolutionary Biology aims to quantify cells in the vertebrae to understand how reproductive physiology impacts bone’s microstructures. This summer I used these micrographs to foray into analysis in ImageJ (FIJI), where I began toying with machine learning methods for quantification. I still have much to learn on this front, but the dedicated time and resources provided through the proctorship allowed me to develop these invaluable new skills.

Polarized micrograph of a macaque vertebra.
Example of machine-learning interface on ImageJ.

It is important to note that this proctorship’s success was possible not only through the mentorship of Andrew Scherer, but also through the generosity of JIAAW scholars, as well as internal and external funding bodies. I would like to thank Laurel Bestock for the loan of her DSLR camera, as well as Peter van Dommelen, Sarah Sharpe and Jess Porter for facilitating the purchase of a high-powered touch screen PC laptop that processed micrographs and ran analytical software with ease. Many thanks are owed to Zachary Dunseth, who lent both his expertise and polarizing microscopes, in addition to the many accessories necessary for microscopic work. I would finally like to thank the Society of Classical Studies Women’s Classical Caucus (SCS/WCC) COVID-19 Relief Fund, which during the most uncertain of times  allowed me to purchase the Leica EZ4D microscope for use in this and ongoing projects. Thank you all for this support.

While missing field work, I am incredibly grateful for this opportunity to spend my summer building new skillsets in archaeological microscopy. The experience gained throughout this process will undoubtedly enhance my researching abilities as I progress through the ScM and PhD.