AUTOMATED SAMPLE PREPARATION AND IN SITU SEQUENCING OF A DNA BIOSIGNATURE FOR ASTROBIOLOGICAL ANALOGUE SAMPLES

Nucleic acids are the primary molecules for storage and retrieval of genetic information for terrestrial life as we know it. DNA is the most stable and widespread nucleic acid, able to survive under optimal conditions for thousands of years. Detection of extraterrestrial DNA via an automated, in situ DNA sample prep and sequencing capability would represent the ultimate biosignature. Currently, two technologies exist which can address this need in a system, Scodaphoresis, and the emerging hand-held, MinION nanopore sequencer from Oxford Nanopore. SCODAPhoresis is able to concentrate very small amounts of DNA, purify it from PCR and enzymatic inhibitors, and allow molecular characterization in an automated fashion. We have utilized SCODAphoresis to extract DNA from previously uncharacterizable samples of astrobiological significance: ice cores from a Norway glacier, and sequence the metagenomic community with Illumina sequencers. We have also used SCODA to isolate and sequence communities from other astrobiological analogues such as the Atacama desert. We are in the early access program evaluating the MinION, and have sequenced bacteria and viruses to very long length. The MionION sequencer could allow for direct sequencing of any DNA purified by SCODA if deployed on a lander or orbiter (such as one that might collect icy material ejected from a Europa or Encedalus). The DNA sequence information could be beamed back, in lieu of a sample return capability.