Extended Data Fig. 2: Sequence read quality for matched 5′ and 3′ PBMC libraries.
From: Mostly natural sequencing-by-synthesis for scRNA-seq using Ultima sequencing
(a) Bar plot of the percent of reads at different quality levels for each sequencing platform and library type along the length of the read, for either Read 1, or Read 2 (or, for Ultima, the subsection of the read corresponding to Read 2), or the full read (up to 200 bases, Ultima only). Annotation of the reads is shown at the bottom. Information to guide UMI trimming from the UMI 3′ end for 3′ libraries (b-d). (b) Rarefaction curves at different UMI lengths and with and without filtering low quality reads. (c) At different UMI lengths, UMI/CBC pairs that have all Read 2s in the same gene. Lower levels suggest UMIs are too short. (d) Number of UMIs at different UMI lengths – a measure of similar UMIs collapsing as length decreases.
