IonTorrent

IonTorrent is a next-generation semiconductor sequencing technology developed by Thermo Fisher Scientific. It differs from other next-generation sequencing platforms by employing a semiconductor-based detection method rather than fluorescence or other optical signals. The core principle of IonTorrent sequencing relies on the detection of hydrogen ions (protons) released during the polymerization of DNA.

The process begins with the preparation of DNA libraries, which are then attached to microbeads. These microbeads are loaded into a microchip containing millions of wells, each designed to hold a single DNA template. During the sequencing-by-synthesis process, DNA polymerase extends a DNA strand in the presence of one of the four deoxyribonucleotide triphosphates (dNTPs). When a dNTP is incorporated into the growing DNA chain, a hydrogen ion is released. This release of ions changes the pH within the well, which is detected by a sensor beneath the well. The sensor translates this pH change into an electrical signal, which is then interpreted as the incorporation of a specific nucleotide. By washing the chip sequentially with each of the four dNTPs, the sequence of the DNA can be determined.

IonTorrent technology offers several advantages, including speed, cost-effectiveness, and a simplified workflow. Its ability to directly detect the chemical byproducts of DNA synthesis makes it a unique and valuable tool in genomics research, diagnostics, and other life science applications. The platform has been widely adopted for various applications, including whole-genome sequencing, exome sequencing, targeted sequencing, and RNA sequencing.