In detail, transposon adapters containing well-defining barcodes and unique molecular identifiers (UMIs) were annealed by mixing 25 μM oligos (P5-UMI-xi5001…5096-ME.fw, Tn5hY-Rd2-Wat-SC3) in 5 μM tris-HCl (pH 8), incubating at 99°C for 5 min, and slowly cooling down to 20°C within 15 min in a thermocycler.