Matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (MALDI-TOF MS)

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The Center for Archaeometry (CfA) is a newly established interfaculty core facility at the University of Tübingen. The CfA combines existing instrumentation and analytical competence from the Working Groups for Archaeometry, Geoarchaeology and Applied Mineralogy in order to facilitate innovative, cross-disciplinary research within the broad spectrum of archaeological research conducted at the University of Tübingen. With the growing integration of palaeoproteomic research into archaeological sciences over the past decade, several Working Groups supported by the CfA are seeking to analyse ancient proteins to further our understanding of the human past. At present we have no dedicated mass spectrometer (MS) to achieve this work and pay commercial prices to analyse our samples. With the establishment of the core facility and the pursuit of ambitious new projects, we are seeking to acquire a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (MALDI-TOF MS). The MALDI-TOF MS is used in the analysis of proteins and other biomolecules, including DNA and carbohydrates. It utilizes ‘soft ionization’ which allows fragile molecules to be analyzed through the vacuum of an MS. This is achieved through the co-crystallization of prepared proteins with a highly absorbing matrix solution. The MS then bombards the crystallized samples with a laser of sufficient energy for the peptides to move through the analyser as singly charged molecular ions which are then measured by a detector. MALDI-TOF MS allows for the rapid measurement of proteins, with the option to spot as many as 384 samples onto a single target plate. MALDI-TOF MS therefore presents a highly time- and cost-efficient means of measuring proteins. The MALDI-TOF MS has become central to peptide mass fingerprinting (PMF) methods, in which proteins are extracted, enzymatically digested into peptides, and measured. In palaeoproteomics, PMF is used to target collagen, keratin, and eggshell specimens that can be matched to published reference libraries for taxonomic identification. Archaeological artefacts of bone, ivory, leather, hide, and shell are often worked beyond the point of morphological identification and PMF becomes an invaluable tool in researching these objects. The proposed MALDI-TOF MS will be overseen by the CfA and housed within the Institute for Archaeological Sciences (Institut für Naturwissenschaftliche Archäologie: INA). While the instrument will be maintained by the core facility it will be invaluable to a range of archaeological projects and Working Groups. The applicability of the MALDI-TOF MS to highly varied archaeological questions will place the instrument at the center of several cutting-edge research projects both internal and external to the University of Tübingen.