title: ctDNA of bladder cancer case 1
design: Start with 550 ng purified cfDNA, quantify by Qubit dsDNA HS; perform single-tube end-repair/A-tailing, then ligate unique-molecular-identifierand unique dual-indexed, T-tailed Y-adapters per kit instructions. Clean up with 1.2 SPRI beads to remove adapter dimers, amplify minimally (612 cycles) with a high-fidelity polymerase, and bead-clean 1.0; QC the library (expected peak ~290320 bp including adapters) and quantify by qPCR or Qubit. pooled libraries at 450 pM were loaded on an Illumina NextSeq for sequencing.