Ancient bacterial DNA (aDNA) in dental calculus from archaeological human remains

The purpose of this study was to identify reactive bacterial aDNA in archaeological human dental calculus. Dental calculus was collected from a middle/late Neolithic human skull from Hulbjerg passage grave, Langeland, Denmark and prepared for transmission electron microscopy (TEM) or gold-labeled antibody TEM. TEM showed calcified, as well as non-calcified bacteria. Immunogold labeling occurred over the cytoplasmic portions of the sectioned bacteria. The result demonstrated that it is possible to identify aDNA sequences from bacteria in archaeological material of considerable age by this technique.