Figure 4: In-ice RNA replication and fidelity.
(a) Enhanced RNA primer extension in ice. Shown are fluorescent primer extension reactions after 25 days of incubation, resolved by denaturing gel electrophoresis. Extension in ice reaches 23 nucleotides (in standard MgCl2 extension buffer) or 32 nucleotides on a longer template in MgSO4 extension buffer (right panel, with inset showing high-sensitivity scan of indicated area) using reduced ribonucleotide triphosphate concentrations (NTPs) (Supplementary Note). (b) High-throughput sequencing of 12 nucleotide extension products reveals comparable replication fidelities and error spectra in solution and in ice.
