How are UMIs read-out during sequencing? What read length is needed?

The UMI sequence (6 nt) and following 4 nt spacer is read-out at the beginning of Read 1. Hence, additional nucleotides at the 5' end of each read will be taken up by the UMI + spacer. We therefore recommend a minimum read length of 75 bp (i.e., SR75) and up to SR150, for sequencing QuantSeq FWD libraries containing UMIs.