###### Abstract  
This article reviews the complementary strategies that are used to decipher the valuable information that is contained in ancient parchment documentary materials. A new trend is molecular analysis, which has given rise to the emerging field of biocodicology, comprising protein and DNA analysis for the identification of the biological origin of the skins that are used for their manufacture. In addition, DNA analysis can identify the microbiome that is present in the object under investigation, which adds value by providing information on its history and state of preservation. In any case, it is important to complement the biomolecular investigations with microscopical and physicochemical analyses. Some of the complementary analytical techniques that are reviewed here, such as elemental analysis by X-ray fluorescence (XRF) with compound-specific analytical methods such as Fourier transform infrared (FTIR) and Raman spectroscopy are advantageous as they can be applied in a non-invasive way and without inducing any changes in the objects. parchment; animal skins; inks; biocodicology; metagenomics; microbiome; conservation; spectroscopy +
Footnote †: journal: Medical Imaging  
_Applied Sciences_  
in addition to the use of lime, was carried out either dry or in tanks where the hides were immersed in brine for a few days to allow for the deep penetration of the salt into the hides [5]. This manufacturing process produces a durable substrate that can survive and be undamaged for centuries. In addition to the raw materials that are used for the manufacture of the parchment, most of the materials that were used for the further production of ancient codices or scrolls were of animal origin: alum-dyed hides, tanned leather, parchment, furs, silk linings, fish glue, casein glue, egg white finish, beeswax and even sinew for making thread [6]. It is worth mentioning that all these materials are prone to biodeterioration. Furthermore, parchment manuscripts were written with inks that were pigmented with iron gall or charcoal or printed with resinous printing inks; they were often illuminated with a wide range of mineral and organic pigments, and they were decorated with metals such as gold or silver and their alloys, depending on their date of manufacture and country of origin [4]. As mentioned above, although parchment is a fairly resilient and durable material, its deterioration may be due to a combination of undergoing exposure to light, high temperatures, humidity and atmospheric pollutants, thereby causing both chemical and structural changes. In addition, parchment is extremely hygroscopic, which makes it very vulnerable to the development of microorganisms if it is exposed to a high level of relative humidity. To study the ancient parchment manuscripts in a comprehensive way, two scientific fields, codicology and the emerging field of biocodicology, can be brought together. Codicology is the study of books and ancient manuscripts as physical objects, especially those that are written on parchment in the codex form, dealing with the materials and techniques that were used to make the manuscripts. By closely examining the physical and chemical attributes of a manuscript, it is possible to establish the materials that were used for its production, writing and illumination, but also to infer its state of preservation, possible subsequent restoration or even its history and provenance. An emerging field that is currently expanding the scope of codicology is biocodicology, which studies the biological information stored in ancient manuscripts [6]. Biocodicology incorporates high-throughput molecular techniques such as proteomics [7], genomics and metagenomics [1; 2; 3; 8]. These technologies make it possible to extract the biological information that has been stored for centuries in ancient parchment manuscripts to better understand how the manuscripts were produced and used throughout history and how this can help to focus our view of the past.