Thesis (M.Sc.)--Chulalongkorn University, 2011

Nucleic Acid Lateral Flow (NALF) is a rapid test for nucleic acid detection that is easy to perform and to interpret. This advantage is suitable for a pathogen diagnosis in low resource settings. However, the major weakness is it has limited sensitivity. Thus, this study aimed to setup and improve sensitivity of NALF to detect HIV-1 nucleic acid. The strategies including UV crosslink, enzyme link gold nanoparticles conjugate and Helicase Dependent Isothermal Amplification (HDA). The NALF platform for HIV-1 detection were setup and optimized. UV exposure was performed to increase the capture probe adherence to the membrane. The results revealed that the streptavidin/biotin combined with UV crosslink method had increased approximately 30% of signal level when compare to streptavidin/biotin alone. Whereas, Non-labeled oligonucleotides combined with UV crosslinking gave a comparable result to the streptavidin/biotin method. HRP linked-gold nanoparticle approach increased approximately 3 folds of signal level or 300% (p<0.05) when compared to the conventional method. HDA amplification using HIV-1 cDNA from clinical samples with known viral load then deteced by the NALF system was able detect at least 445 copies/mL of HIV-1 RNA from plasma (pre-amplification template).