Real-Time NASBA

NASBA is an isothermal nucleic acid amplifi cation method that is particularly suited to detection and quantifi cation of genomic, ribosomal or messenger RNA. The product of NASBA is single-stranded RNA of opposite sense to the original target. The fi rst developed NASBA methods relied on liquid or gel-based probe-hybridisation for post-amplifi cation detection of products. More recently, real-time procedures incorporating amplifi cation and detection in a single step have been reported and applied to a wide range of targets. Thus real-time NASBA has proved to be the basis of sensitive and specifi c assays for detection, quantifi cation and analysis of RNA (and in one case DNA) targets. Molecular beacons have been utilised for detection of NASBA products in all published real-time procedures whether for commercially-available kits or for in-house diagnostic assays. As experience in design of such fl uorescent-labelled probes increases and fl uorimeters suitable for their detection become widely available, realtime NASBA methodology will be confi rmed as a suitable alternative to other real-time amplifi cation methods such as reverse transcriptase PCR (RT-PCR). caister.com/pcrbooks