Rapid detection of dengue viral RNA by nucleic acid sequence-based amplification (NASBA)

The suitability of RNA amplification by nucleic acid sequence-based amplification (NASBA) for the detection of dengue viral RNA was investigated. A set of primers and probe were synthesized, based on a selected RNA sequence from the non-coding region at the 3′ end of dengue viral RNA, and was used in the NASBA assay. The NASBA reaction product was then determined by agarose gel electrophoresis and electrochemiluminescence (ECL) signal count. The sensitivity of the NASBA assay was equal to 1 PFU/ml for all four dengue virus serotypes. There was no false positive result with Japanese encephalitis (JE) virus. This method was used successfully to detect dengue virus in the infected tissue culture cells. This test will be useful for the detection of dengue viruses in the clinical specimens.