Scientists recently confirmed that it is possible to collect cell samples from historical parchment manuscripts and conduct genetic analysis without damaging them. The method has been used successfully on documents dating back 1,300 years and is expected to reveal more details about trade routes, agricultural practices and the animals used to make parchment.
Parchment is a writing material made of animal leather. It has been widely used in parts of Europe, the Middle East and Africa for thousands of years. It is commonly used in legal documents, maps and other records. Because the material itself comes from animal skin, researchers have long known that genetic information can be extracted from parchment to trace the time, place and context of the manuscript's production.
Tim Stinson, corresponding author of the study and associate professor of English at North Carolina State University, said that parchment not only records rich historical texts, but the genetic information it contains also opens a new window for us to understand the past. By analyzing these DNA fragments, researchers can not only determine the types and origins of animals used in the production of manuscripts, but also help infer the geographical and temporal distribution of the documents.
Matthew Breen, co-author of the paper and professor of comparative tumor genetics at the College of Veterinary Medicine at North Carolina State University, pointed out that the continuous use of parchment spans an extremely long time span and is often accompanied by detailed historical records. Therefore, the genetic information contained in it can also help the academic community reconstruct the process of livestock domestication and breed improvement. These data are expected to reveal the evolution trajectories of different agricultural and animal husbandry systems over the long historical process, including the prevalence of livestock diseases and their transmission methods.
In the past, one of the biggest challenges facing this emerging field of research was the difficulty of obtaining permission to sample precious manuscripts: collection institutions were generally concerned that sampling would cause irreversible damage to the documents. Stinson said the core value of the new technology is to prove that sufficient genetic material can be collected without affecting the integrity of the documentation, which opens new doors for related research.
In the latest study, scientists used a non-destructive sampling scheme to sample 91 parchment manuscripts from the Rubenstein Library at Duke University. The manuscripts come from a wide range of sources, ranging from England to Ethiopia, and date from the late 8th century AD to the early 20th century, covering a historical span of more than a thousand years.
In terms of specific operation, the research team used a cytology brush, which is commonly used in clinical cervical smear examination, to collect residual cells and trace tissues by gently rubbing on the surface of parchment paper. Brin said that this type of cytology brush can efficiently collect cell materials in a dry state without damaging the structural integrity of the sampled artifacts, making it very suitable for micro-sampling of fragile documents.
After the collection is completed, scientists separate cells from the material collected on the brush and use forensic-grade high-throughput sequencing (next-generation sequencing) technology to recover and amplify the genetic sequences. Through these cutting-edge genetic analysis methods, the team was able to reconstruct DNA information with research value from a very small amount of samples, providing a new chain of evidence for the animal origin and related historical circumstances behind the manuscript.
Stinson emphasized that the research team is actually applying the most advanced genetic analysis technology to the study of historical documents to expand our understanding of past social, cultural and agricultural practices through empirical data. In his opinion, the genetic information hidden in the parchment constitutes an "animal archive" that has not yet been fully developed, and is expected to complement traditional philology and historical research.
Brin said the results show that a considerable amount of informative genetic data can be extracted from these manuscripts, all without compromising the literature. He hopes that this achievement will enhance the trust of libraries, archives and other document preservation institutions in related genetic research, thereby promoting the opening of more collections to the scientific community.
The research team is currently seeking further research funding to explore the potential of this area on a larger scale. They believe that the genetic information contained in the parchments is a vast and underutilized repository of historical information, and that the current study is just the beginning of this interdisciplinary exploration.
Brin said the opportunity at hand was "extraordinary": an emerging direction that closely linked genetics, forensics, animal science, history and medieval studies. As more manuscripts are included in the analysis, DNA data from ancient "animal archives" is expected to reshape our understanding of historical trade networks, pastoral structures, and cultural exchange paths.