Overview of the experimental setup and bioinformatic pipeline. (A) Schematics of DNA sample preparation and sequencing. High-molecular-weight gDNA was extracted from peripheral blood mononuclear cells (PBMCs), isolated monocytes, or the HG002 Epstein–Barr virus lymphoblastoid cell line (EBV-LCL). The DNA was used as input for the preparation of ultra long-read ONT sequencing libraries. Sequencing was performed using an adaptive sampling strategy to enrich for reads mapping to the IGH locus. (B) Read depth from the four donors on a custom IGH reference. (C) Outline of the bioinformatic pipeline used to generate one-contig haplotype-resolved IGH assemblies.