Cleanup of enzymatic reactions and size selection of DNA fragments are common steps in the vast majority of NGS library preparation workflows. NucleoMag NGS Clean-up and Size Select employs scalable magnetic bead technology to enable efficient cleanup and tunable size selection of NGS libraries for an array of sequencing applications. The flexible protocol allows for single- or double-sided size selection and enrichment of fragments of a given size via adjustment of bead-to-sample volume ratios.