The NEBNex®t Ultra™ II FS DNA Library Prep Kit for Illumina provides a fragmentation system: a fast and reliable solution for DNA fragmentation and library construction. A new DNA fragmentation reagent is combined with end repair and dA-tailing reagents, allowing these steps to be performed in the same tube, with no clean-ups or sample loss. The same fragmentation protocol is used for any input amount (100 pg–500 ng), or GC content. The kit also includes the NEBNext Ultra II Ligation Master Mix for adaptor ligation, the NEBNext Ultra II Q5® Master Mix for uniform, high-fidelity library amplification, and the gold standard SPRIselect size selection and clean-up beads. Please note that adaptors and primers are not included in the kit and are available separately.