Figure 1.

Flowcells were maintained above freezing using body heat for the outbound eleven ski days. (A) Pulks (including the DNA sequencing equipment) were pulled by ski for seven days on the outbound journey to the “Base camp” on the northern edge of the ice cap. The return journey was reduced to four days due to more favourable ski and weather conditions. (B) Temperature log of the flowcells from leaving the UK to the start of the second sequencing run. During Day −4 the flowcells were kept in a polystyrene box with cool packs equilibrated to 4 °C and put in the hold during the flight. Days −3 to 0 were spent travelling to and staying at a hostel where flowcells were kept indoors at room temperature. Days 1 to 7 were spent traversing the icecap. Spikes in temperature correspond to night time where flowcells were kept inside the sleeping bag. Days 8 to 11 were spent at “Base camp” on the northern edge of the ice cap. Sequencing runs #1 and #2 (red lines) occurred at the base camp on Day 8 and Day 11.