Novel pH sensing semiconductor for point-of-care detection of HIV-1 viremia.
The timely detection of viremia in HIV-infected patients receiving antiviral treatment is key to ensuring effective therapy and preventing the emergence of drug resistance. In high HIV burden settings, the cost and complexity of diagnostics limit their availability. We have developed a novel complementary metal-oxide semiconductor (CMOS) chip based, pH-mediated, point-of-care HIV-1 viral load monitoring assay that simultaneously amplifies and detects HIV-1 RNA. A novel low-buffer HIV-1 pH-LAMP (loop-mediated isothermal amplification) assay was optimised and incorporated into a pH sensitive CMOS chip. Screening of 991 clinical samples (164 on the chip) yielded a sensitivity of 95% (in vitro) and 88.8% (on-chip) at >1000 RNA copies/reaction across a broad spectrum of HIV-1 viral clades. Median time to detection was 20.8 minutes in samples with >1000 copies RNA. The sensitivity, specificity and reproducibility are close to that required to produce a point-of-care device which would be of benefit in resource poor regions, and could be performed on an USB stick or similar low power device.
Division of Infectious Diseases, Imperial College, London, England.
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R
Gurrala
DNA Electronics Ltd, Wood Lane, London, England.
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Z
Lang
DNA Electronics Ltd, Wood Lane, London, England.
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L
Shepherd
DNA Electronics Ltd, Wood Lane, London, England.
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D
Davidson
DNA Electronics Ltd, Wood Lane, London, England.
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E
Harrison
Division of Infectious Diseases, Imperial College, London, England.
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M
McClure
Division of Infectious Diseases, Imperial College, London, England.
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S
Kaye
DNA Electronics Ltd, Wood Lane, London, England.|Department of Bioengineering, Imperial College, London, England.
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C
Toumazou
Division of Infectious Diseases, Imperial College, London, England.
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GS
Cooke
D015492:AIDS Serodiagnosis / Q000295:instrumentation* / Q000379:methods; D015658:HIV Infections / Q000175:diagnosis* / Q000235:genetics / Q000821:virology; D015497:HIV-1 / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008670:Metals / Q000737:chemistry; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D010087:Oxides / Q000737:chemistry; D019095:Point-of-Care Systems; D012367:RNA, Viral / Q000235:genetics; D012666:Semiconductors; D014766:Viremia / Q000175:diagnosis* / Q000235:genetics / Q000821:virology
D008670:Metals; D010087:Oxides; D012367:RNA, Viral