The EpiNext™ DNA Size Selection Kit is a complete set of optimized reagents for quick removal of DNA fragments of <150 bps for library preparation in next generation sequencing applications. The kit utilizes magnetic bead technology and is suitable for Illumina, Life Technologies (SOLiD), Ion Torrent, and Roche/454 platforms. It can also be used for removing undesired larger DNA fragments by optimizing the bead to DNA volume ratio accordingly. The indicated number of reactions can be performed for a standard 50 µl solution input DNA sample. The kit has the following advantages:

• Optimized fragment selection chemistries: Complete separation of DNA fragments according to size. Suitable for Illumina, Ion Torrent, SOLiD and Roche/454 platforms.
• Fast and straightforward: Size selection procedure can be finished within 30 min. No gels, columns or centrifugation are needed.
• Efficient removal of primer-dimers: No need for further clean-up steps.
• High recovery of targeted DNA fragments: Higher than 85% recovery of input DNA fragments. 
• Manual and automation friendly: Scalable for use in single tube or 96-well plate format.

Background Information
DNA size selection is necessary after DNA shearing as part of the library construction process for next generation sequencing, regardless of the platform used. Obtaining high recovery of selected DNA fragments is critical for the reduction of sequencing bias. 

Principle & Procedure
This kit includes all reagents required at each step of the workflow for DNA size selection. The size of DNA fragments bound to the included MQ Binding Beads is based on the ratio of MQ beads to the DNA sample solution. Optimization of MQ bead ratio to input DNA, allows for the removal of larger or smaller DNA fragments and recovery of desired target size DNA fragments.

Starting Materials
DNA fragments of various lengths. Input amount can be from 0.1 ng to 1 µg.  

Fig. 1. Workflow of the EpiNext™ DNA Size Selection Kit.

Fig. 2. Size selection of DNA fragments: Human Placenta DNA was sheared to 100-700 bps in length with peak size of about 300 bps (A). A target peak size of 500 bps (B) was selected using the EpiNext™ DNA Size Selection Kit.