Christopher B. Stone and James B. Mahony
Nucleic acid amplification tests (NATs) are rapidly becoming the cornerstone of clinical virology laboratories around the world. While polymerase chain reaction (PCR) amplification has served laboratories well since the 1990s, providing sensitive and specific tests to detect clinically important viruses, PCR tests have significant disadvantages as they are cumbersome, labor intensive, and relatively slow compared with newer isothermal amplification methods. Commercially available multiplex PCR tests have recently become popular and are being implemented in many laboratories. Following the introduction of the first isothermal amplification formats of the 1990s, newer isothermal methods have been developed including loop-mediated amplification (LAMP) or recombinase polymerase amplification (RPA), which can yield results in as little as 10 to 20 minutes. Specimen preparation has now fallen behind advances in amplification technology with specimen preparation now taking longer than these newer isothermal amplification methods. Coupled with advances in amplicon detection employing microfluidics, biosensors and nanotechnology, these new isothermal amplification methods provide unique opportunities for the development of new laboratory-based tests and inexpensive, one-time use, point-of-care (POC) diagnostics.