Isolation of nucleic acids and cultures from fossil ice and permafrost
A review of recent claims about viable cells and microbial nucleic acids obtained from ice and permafrost hundreds to millions of years old. We also outline a set of precautions and controls to help ensure authenticity of future studies.
Mar 18, 2004
Authors: E. Willerslev, A.J. Hansen and H.N. Poinar
Trends in Ecology and Evolution, Vol. 19, Issue 3, March 2004, pp. 141-147. DOI: https://doi.org/10.1016/j.tree.2003.11.010
Owing to their constant low temperatures, glacial ice and permafrost might contain the oldest nucleic acids and microbial cells on Earth, which could prove key to reconstructing past ecosystems and for the planning of missions to other planets. However, recent claims concerning viable cells and microbial nucleic acids obtained from ice- and permafrost cores from hundreds of thousands to millions of years old are not properly authenticated and the findings could be the result of contamination. Here, we discuss the processes that restrict the long-term survival of DNA and/or RNA molecules in ice and permafrost, and highlight sources of contamination that could result in false claims. Additionally, we present a set of precautions, controls and criteria to help ensure that future cultures and sequences are authentic.