One-step purification of nucleic acid for gene expression analysis via Immiscible Filtration Assisted by Surface Tension (IFAST).

The extraction and purification of nucleic acids from complex samples (e.g. blood, biopsied tissue, cultured cells, food) is an essential prerequisite for many applications in biology including genotyping, transcriptional analysis, systems biology, epigenetic analysis, and virus/bacterial detection. In this report, we describe a new process of nucleic acid extraction that utilizes "pinned" aqueous/organic liquid interfaces in microchannels to streamline the extraction mechanism, replacing all washing steps with a single traverse of an immiscible fluid barrier, termed Immiscible Filtration Assisted by Surface Tension (IFAST). Nucleic acids in biological samples are bound to paramagnetic particles and then drawn across the IFAST device (or array of IFAST devices) using a magnet. While the strength of the IFAST barrier is suitable for separation of nucleic acids from lysate in its current embodiment, its permeability can be selectively adapted by adjusting the surface tensions/energies associated with the cell lysate, the immiscible phase, and the device surface, enabling future expansion to other non-nucleic acid applications. Importantly, processing time is reduced from 15-45 minutes to less than 5 minutes while maintaining purity, yield, and scalability equal to or better than prevailing methods. Operation is extremely simple and no additional lab infrastructure is required. The IFAST technology thus significantly enhances researchers' abilities to isolate and analyze nucleic acids, a process which is critical and ubiquitous in an extensive array of scientific fields. © The Royal Society of Chemistry 2011