NGS library size selection at a certain size range can be enriched using Solid Phase Reversible Immobilization (SPRI) beads. Kits are available for both short-read sequencing (illumina, MGI) and long-read sequencing (PacBio, Oxford Nanopore).

Size selection is a selective capture of DNA fragments of a specific range of size for next-generation sequencing (NGS) library preparations, PCR, ChIP assay, DNA ligations, endonuclease digestions, adapter removal, and other genomics and molecular biology applications. DNA size selection is preferred after NGS library prep in most of the cases. The NGS library preparation is related to the quality of the sequencing data. Precise NGS size selection can increase sequencing efficiency, improve data quality, and reduce costs.

There are two types of sequencing technologies: short-read sequencing and long-read sequencing. Short-read sequencing uses DNA libraries that contain small insert DNA fragments of similar sizes, usually several hundred base pairs. The sequencing efficiency can be improved if the size selection is in the right range. Long-read sequencing uses a large DNA fragment as input and makes very long reads. Usually, size selection is preferred to remove smaller fragments. 

The magnetic beads technology uses paramagnetic particles, also known as SPRI beads, to bind DNA reversibly and selectively. DNA fragments can be size-selected and purified by changing the properties of the magnetic beads or SPRI beads. The magnetic beads can easily separate the beads-binding DNA from the contaminants and unwanted components in the samples. The samples after DNA size selection are free of contaminants such as buffer components, enzymes, proteins, salts, dNTPs, primers, and adapters. Our proprietary magnetic beads reagents improve yield, selectivity, and reproducibility.