Nucleic Acid Sequencing Under Mars-Like Conditions

All known life uses informational polymers based on nucleic acids. Future missions to Mars and Ocean Worlds such as Enceladus and/or Europa may target these or related polymers in the search for extant life beyond Earth. Nanopore-based devices represent a promising approach for sensing and characterizing these, and possibly other, biomarkers. Here we demonstrate low-input (200 pg)DNA sequencing, equivalent to extraction from 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> Bacillus subtilis spores at 5 percent extraction yield, using the Oxford Nanopore MinION in a thermal vacuum chamber under Mars-like temperature (-60°C), atmosphere (100% CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ), and pressure (400 to 500 Pa). Current limits of detection correspond to 2 to 5 pg DNA. With additional advances in nucleic acid extraction and library preparation efficiency, a sequencing-based approach to life detection will be viable at cell densities representative of the most extreme Mars analog environments here on Earth.