Technical note: PCR analysis of minimum target amount of ancient DNA

The study of ancient DNA plays an important role in archaeological and palaeontological research as well as in pathology and forensics. Here, we present a new tool for ancient DNA analysis, which overcomes contamination problems, DNA degradation, and the negative effects of PCR inhibitors while reducing the amount of starting target material in the picogram range. Ancient bone samples from four Egyptian mummies were examined by combining laser microdissection, conventional DNA extraction, and low-volume PCR. Initially, several bone particles (osteons) in the micrometer range were extracted by laser microdissection. Subsequently, ancient DNA amplification was performed to verify our extraction method. Amelogenin and beta-actin gene specific fragments were amplified via low-volume PCR in a total reaction volume of 1 microl. Results of microdissected mummy DNA samples were compared to mummy DNA, which was extracted using a standard DNA extraction method based on pulverization of bone material. Our results highlight the combination of laser microdissection and low-volume PCR as a promising new technique in ancient DNA analysis.