Researchers at Imperial College London and DNA Electronics, a company with offices in London, UK and Carlsbad, CA, developed a computer USB stick that takes a drop of blood and measures the amount of HIV particles.
The chip produces results within 30 minutes, while the average in a test of nearly 1000 samples was only 21 minutes. According to the company, the accuracy is good enough for it to be used to monitor viral loads in patients taking anti-retroviral drugs to see whether the therapy’s effect is holding up.
The chip amplifies HIV-1 RNA and uses an assay that changes the sample’s acidity if the target RNA is present to generate an electrical signal. This signal travels down the USB stick and to the computer where an application registers it as having detected the virus.
From the study abstract in journal Scientific Reports:
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.
Study in Scientific Reports: Novel pH sensing semiconductor for point-of-care detection of HIV-1 viremia…