This Twist Library Preparation Kit provides the reagents needed to prepare genomic DNA (gDNA) libraries using enzymatic gDNA fragmentation and unique molecular identifiers (UMIs). The Twist UMI Adapter system consists of Twist UMI Adapters and Twist Unique Dual Indexed (UDI) Primers. This manual details the steps for generating the amplified, indexed libraries with UMI tags for downstream target enrichment and sequencing on Illumina next-generation sequencing (NGS) systems. This library preparation protocol is optimized for use with Twist Target Enrichment Kits and should only be performed with reagents specified or their equivalents.