to BioTechniques free email alert service to receive content updates.
Beyond ancient microbial DNA: nonnucleotidic biomolecules for paleomicrobiology
 
Thi-Nguyen-Ny Tran, Gérard Aboudharam, Didier Raoult, and Michel Drancourt
Full Text (PDF)
  • Impact factor >0.5 (2009 value)

  • Strength of evidence:
    1. Good evidence of authenticity:

      1. Detection of one or more macromolecules

      2. Independent verification by an unrelated technique

      3. Precautions to avoiding contamination

      4. Negative controls

    2. Moderate evidence of authenticity:

      1. Detection of one or more macromolecules

      2. Precautions to avoiding contamination

      3. Negative controls

    3. Low evidence of authenticity:

      1. Detection of one or more macromolecules

      2. Precautions to avoiding contamination

    Quality of evidence:
    1. Evidence from two independent teams using agreed protocols

    2. Evidence from one laboratory using agreed protocols

    3. Evidence from one laboratory using nonagreed protocols

    (Based on Box 2, “System used in this article to assess authenticity of data,” Reference 1).









    Sources of ancient nonnucleotidic microbial biomolecules

    Bone tissue is the most common source for ancient microbial proteins preserved in archaeological specimens (17-19)(24-29). Mummified tissues are another source of ancient proteins; an autopsy of an Egyptian mummy dating back to the late Ptolemaic period (second to first centuries BC) revealed a bundle of linen bandages enveloping a hollow muscular organ, identified as the stomach, which was used to make the diagnosis of cysticercosis (30). Mummified muscle (31), skin (15), brain, and lung (32) have also been used for protein-based identification of microbes. Hair (33) and teeth (34) are two other common sources. In these tissues, degradation of the ancient proteins is a challenge to their retrieval and analysis (14). In our laboratory, we use dental pulp as the material of choice for paleomicrobiology and developed a simple protocol for protein extraction from this tissue (Figures 2 and 3). It is of note that teeth are the only body parts that remain after the bones have disintegrated. For instance, only teeth remained in the Early Upper Paleolithic site of Kostenski in Eastern Europe, which proved critical in understanding the dispersal of modern humans even when morphological identification was impossible (35). However, dental pulp is obtained in small quantities, especially in some animals such as guinea pigs, rats, and cats. Extracted ancient protein should be concentrated, and the concentration should be measured using the Bradford protocol (36). This protocol is easy to perform, but is time-consuming due to the need to dilute the samples for dosage.

      1    2    3    4    5