Freezing at -800 degrees C distorts the DNA composition of bacterial communities in intestinal samples

Curr Issues Intest Microbiol. 2006 Mar;7(1):29-34.

Abstract

Terminal-restriction fragment length polymorphism (T-RFLP) was used to evaluate how to store intestinal specimens for bacterial community analysis. Bacterial communities are increasingly often described by means of DNA-based methods and it is common practice to store intestinal or faecal specimens either at -20 degrees C or -80 degrees C. In this study, samples of intestines from five different pigs were stored at -80 degrees C and -20 degrees C, respectively and a thawing and freezing procedure was carried out three times for each intestinal per pig per temperature. The cumulative sum of the T-RFLP peak heights (T-RF intensities) decreased as the temperature decreased. The composition of the bacterial community changed when stored at -80 degrees C compared to the samples stored at -20 degrees C. Thus it is recommended from this study that samples of intestinal content are stored at -20 degrees C before use for bacterial community analysis, instead of the current practice at -80 degrees C.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • DNA Fingerprinting
  • DNA, Bacterial / analysis*
  • DNA, Bacterial / genetics*
  • Feces / chemistry
  • Feces / microbiology*
  • Freezing*
  • Polymorphism, Restriction Fragment Length
  • Specimen Handling*
  • Swine

Substances

  • DNA, Bacterial