When are UMIs useful for library preparation?

UMIs are most useful for evaluating and removing PCR duplicates in the following cases:

• Low input amounts (≤10 ng total RNA)

• FFPE RNA

• QuantSeq-Flex targeted RNA-Seq library prep (can be incorporated in custom primers – See QuantSeq-Flex V2 User Guide)

• For very high sequencing depth (e.g., ≥30 M reads per sample. Note the recommended minimum read depth for QuantSeq is 3 – 4 M reads per sample).

UMIs are usually not required when input amounts are ≥50 ng. For input amounts of 10 – 50 ng of total RNA, UMIs could be recommended for samples with reduced or variable RNA quality.