Purification of nucleic acids using isotachophoresis

• Efficient and automated sample preparation is a major bottleneck in NA analyses.
• ITP uses electric field to selectively extract and purify NAs.
• ITP-purified NA samples are compatible with downstream analytical assays.
• Guidelines for the design of lysis and ITP separation chemistry are presented.
• Examples of ITP sample preparation from blood, urine, and cell culture are reviewed.

Reviewed are methods of nucleic acid (NA) extraction and sample preparation using an electrophoretic purification and focusing method called isotachophoresis (ITP). ITP requires no special surface chemistries or geometric structures, and can be achieved in a compact system with no moving parts. ITP is also compatible with a wide range of samples and lysing methods. Described are general principles of ITP, considerations around the application of ITP to biological samples (e.g., blood, urine and saliva), ITP electrolyte design considerations for fast and selective NA purification, and examples of ITP compatible lysing methods. Several of the challenges associated with purification of NAs are presented as well as methods to address these. Lastly, specific examples of lysing methods and ITP chemistries are described for purification of NA including host and pathogenic DNA, pathogenic rRNA, and host micro-RNA from complex sample matrices.