Fig. 2.

Results of optimization of PCR enzyme. Two PCR enzymes, Platinum SuperFi II PCR Master Mix (PSFi II, Thermo Fisher Scientific, MA, USA) and KOD One PCR Master Mix (KOD One, TOYOBO, Osaka, Japan) were tested as candidates. To evaluate the PCR fidelity of these enzymes, we tested whether the correct lineage can be detected using 500 copies per reaction of wild-type synthetic RNA (TwistBiosciences, CA, USA). Stacked bar chart indicates lineage composition identified using PSFi II (left half bars, n = 3) and KOD One (right half bars, n = 3). Grey and black show wild-type and undefined lineages (wild-type with mutation(s) caused by PCR errors), respectively. KOD One detected fewer undefined lineages, indicating fewer PCR errors.