Continuous increases in throughput of next generation sequencing (NGS) technologies enable deeper and faster sequencing of large genomes such as human. Additionally, higher sequencing throughput allows for the simultaneous sequencing of multiple small genomes, targeted loci on large genomes, as well as hundreds to thousands of amplicons. This broad range of applications enabled by NGS requires flexible library construction workflows that have minimal bias and generate high library yields. To address this need, we have developed a series of new adaptors and reagents. The novel NEBNext® adaptors, compatible with sequencing on the Illumina platform, offer significant flexibilities in single plex or multiplex library preparation. In addition, the new NEBNext® reagents further simplify library preparation workflows, increase library yield, and are automation-friendly.