library_construction_protocol: Ini-seq2 Heavy-Light and Light-Light fraction were isolated by isopycnic centrifugation, desolted and precipitated.  SNS-seq samples were processed as descirbed in Akerman et al. Nature Communications volume 11, Article number: 4826 (2020). Libraries were prepared with NEBNext® Ultra™ II DNA Library Prep Kit for Illumina (NEB, E7645S)