Lo CLH, Yip SP, Cheng PKC, To TSS, Lim WWL, Leung PHM. One-step rapid reverse transcription-PCR assay for detecting and typing dengue viruses with GC tail and induced fluorescence resonance energy transfer techniques for melting temperature and color multiplexing.
Clin Chem 2007;
53:594-9. [PMID:
17317885 DOI:
10.1373/clinchem.2006.077446]
[Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND
Dengue fever is an arthropod-borne infection caused by dengue viruses (DVs; DEN-1 to DEN-4). Early diagnosis is critical to prevent severe disease progression and the spreading of DV because no vaccine or specific treatment is available; therefore, a rapid and specific diagnostic assay capable of detecting and typing all serotypes would be ideal.
METHODS
We amplified RNA samples from all 4 DV serotypes and Japanese encephalitis virus with 4 serotype-specific forward primers and a universal species-specific reverse primer. DEN-1 and DEN-3 forward primers were labeled at their 5' ends with BODIPY 630/650 and Cy5.5, respectively. DEN-1 and DEN-3 amplicons were detected by their characteristic emission generated from induced fluorescence resonance energy transfer. The presence of DEN-2 and DEN-4 amplicons was indicated by SYBR Green I (SGI) signals at specific amplicon melting temperatures (T(m)s).
RESULTS
Fluorescence signals with specific emission wavelengths were obtained from DEN-1 and DEN-3. SGI melting profiles showed a T(m) difference between DEN-2 and DEN-4 of 4.7 degrees C, which was sufficient for differentiating these 2 serotypes. The primers did not amplify the Japanese encephalitis virus. The detection limits of DEN-1 to DEN-4 were 1.64 x 10(-4), 1.05 x 10(-3), 8.15 x 10(-4), and 5.80 x 10(-3) plaque-forming units per reaction, respectively. The assay had a dynamic range of 10(3)-10(8) plaque-forming units/L and could be performed in 2 h.
CONCLUSIONS
A single-tube, 1-step reverse transcription-PCR assay based on T(m) and color multiplexing was developed for detecting and typing all 4 DV serotypes.
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