An assessment of the long-term preservation of the DNA of a bacterial pathogen in ethanol-preserved archival material.

To examine the potential for DNA recovery from spirit-preserved medical material, a set of specimens from the Hunterian Collection of the Royal College of Surgeons was investigated. Using a range of DNA extraction techniques and the PCR, no replicable positive amplifications were made from this material of either human or Helicobacter DNA. Experiments with modern stomach biopsies of H. pylori-positive patients suggest that the bacterial DNA is typically present in a much lower concentration (10(3)-fold) than that of the host. The potential for recovery of this organism from spirit specimens is therefore low. The absence of DNA in this material is probably due to several factors, chiefly the incomplete fixation of the specimen by the ethanol storage fluid. Studies such as this demonstrate the need for a good understanding of specimen history when working with archival material.