Molecular-level dengue fever diagnostics via a combination of RT-LAMP and paper-based devices

This paper describes the development of an inexpensive, but robust and easy-to-use point-of-care diagnostic device that can be used for the detection of dengue fever at the molecular level (i.e., the detection of dengue virus via using a piece of paper). To date, the clinical diagnosis of dengue fever mainly relies on ELISA-based examinations for a specific antigen. However, the protein-based diagnostics is at the relatively late stage, and it is needed to develop a simple and low-cost diagnostic device for the detection of dengue fever at the early stage after the infection. Here, we have developed a procedure for monitoring dengue virus serotype 2 RNA (in the buffer system), including: i) amplifying the nucleic acids via RT-LAMP (reverse transcription loop-mediated isothermal amplification), and ii) examining the amplified products via a colorimetric assay in paper. We have demonstrated the ability to amplify dengue virus via RT-LAMP with the virus concentration of 60 PFU/mL; the current results indicated that this paper-based diagnostic device was capable of detecting the RT-LAMP products in the buffer system with the concentration of 300 ng/mL.