COMMUNITY

Ivory is a highly prized material in many cultures since it can be carved into intricate designs and have a highly polished surface. Due to its popularity, the animals from which ivory can be sourced are under threat of extinction. Identification of ivory species is not only important for CITES compliance, it can also provide information about the context in which a work was created. Here, we have developed a minimally invasive workflow to remove minimal amounts of material from precious objects and, using high-resolution mass spectrometry–based proteomics, identified the taxonomy of ivory and bone objects from The Metropolitan Museum of Art collection dating from as early as 4000 B.C. We built a proteomic database of underrepresented species based on exemplars from the American Museum of Natural History, and proposed alternative data analysis workflows for samples containing inconsistently preserved organic material. This application demonstrates extensive ivory species identification using proteomics to unlock sequence uncertainties, e.g., Leu/Ile discrimination.

Microbial communities reside at the interface between humans and their environment. Whether the microbiome can be leveraged to gain information on human interaction with museum objects is unclear. To investigate this, we selected objects from the Museum für Naturkunde and the Pergamonmuseum in Berlin, Germany, varying in material and size. Using swabs, we collected 126 samples from natural and cultural heritage objects, which were analyzed through 16S rRNA sequencing. By comparing the microbial composition of touched and untouched objects, we identified a microbial signature associated with human skin microbes. Applying this signature to cultural heritage objects, we identified areas with varying degrees of exposure to human contact on the Ishtar gate and Sam'al gate lions. Furthermore, we differentiated objects touched by two different individuals. Our findings demonstrate that the microbiome of museum objects provides insights into the level of human contact, crucial for conservation, heritage science, and potentially provenance research.

The exceptional and exciting occurrence of organic food residues inside large nineteenth century alkaline-glazed stoneware vessels from the Old Edgefield district, some also signed by enslaved potter and poet David Drake, has offered a unique opportunity to study those residues as anthropological evidence of the jars’ contents (e.g., preserved meat, fat, eggs, etc.), potentially offering information on the use of the jars and the lifestyle of the people that used them. Residues scraped from the jars’ surfaces were analyzed in the Department of Scientific Research of The Met to evaluate their composition, assess contaminations and clues to their condition (e.g., presence and extent of degradation products), all informing of the next process to further characterize the residue.

As part of the exhibition, Hear Me Now: The Black Potters of Old Edgefield, South Carolina, The Met’s Department of Scientific Research (DSR) investigated organic food residues found inside large nineteenth-century alkaline-glazed stoneware vessels from the Old Edgefield District, South Carolina. “Examining Storage Jars from the American South” describes the driving questions about the jars’ use and the users’ lifestyle. Investigations reported in “The Inside (and Outside) Scoop: Scientific Analysis of Food Residues Inside the Jars from Old Edgefield, South Carolina” established that the heterogeneous residues are mostly oily materials with solid materials of various unknown origins. We hoped to gain more information about the jars’ contents from these residues, but to do so we need the sophisticated tools and expertise of our collaborators through ARCHE.

Little is known about structural alterations of proteins within the polymeric films of paints. For the first time, hydrogen‑deuterium exchange mass spectrometry (HDX-MS) was implemented to explore the conformational alterations of proteins resulting from their interaction with inorganic pigments within the early stages of the paint film formation. Intact protein analysis and bottom-up electrospray-ionisation mass spectrometry strategies combined with progressively increasing deuterium incubation times were used to compare the protein structures of the model protein hen egg-white lysozyme (HEWL) extracted from newly dried non-pigmented films and newly dried films made from a freshly made mixture of HEWL with lead white pigment (2PbCO3 Pb(OH)2). The action of other pigments was also investigated, expanding the HDX study with a global approach to paint models of HEWL mixed with zinc white (ZnO), cinnabar (HgS) and red lead (Pb3O4) pigments. The results show structural modifications of HEWL induced by the interaction with the pigment metal ions during the paint formulation after drying and prior to ageing. Both the charge distribution of HEWL proteoforms, its oxidation rate and its deuterium absorption rate, were influenced by the pigment type, providing the first insights into the correlation of pigment type/metal cation to specific chemistries related to protein stability.

Biocodicology, the study of the biological information stored in manuscripts, ofers the possibility of interrogating manuscripts in novel ways. Exploring the biological data associated to parchment documents will add a deeper level of understanding and interpretation to these invaluable objects, revealing information about book production, livestock economies, handling, conservation and the historic use of the object. As biotechnological methods continue to improve we hope that biocodicology will become a highly relevant discipline in manuscript studies, contributing an additional perspective to the current scholarship. We hope that this review will act as a catalyst enabling further interactions between the heritage science community, manuscript scholars, curators and conservators.