Nucleic Acid Sequence-Based Amplification

Nucleic acid sequence-based amplification (NASBA; bioM�rieux, Boxtel, The Netherlands) is a commercially available amplification procedure that uses RNA as the target. It makes use of the simultaneous enzymatic activities of avian myeloblastosis virus reverse transcriptase (AMV-RT), RNase H, and T7 RNA polymerase, under isothermal conditions. The constant temperature maintained throughout the amplification reaction allows each step of the reaction to proceed as soon as an amplification intermediate becomes available. Products of NASBA are single stranded and, thus, can be applied to detection formats using probe hybridization without any denaturation step.