The mChip is a new cheap, highly portable blood test and has proven to be as accurate as expensive hospital-based analyses in detecting HIV, syphilis and other infectious diseases Researchers tested prototypes of the credit card-sized lab-on-a-chip with hundreds of patients in Rwanda, reporting nearly 100% accuracy.
This new mChip could help knock down three barriers to effective delivery of healthcare into the world’s poorest regions: difficult access, high costs and long delays for results.
Lead developer and professor at Columbia Universty Samuel Sia was reported to say “The idea was to make a large class of diagnostic tests accessible to patients in any setting in the world, rather than forcing them to go to a clinic to draw blood and then wait days for their results,”The findings were published in Nature Medicine.
With a projected production cost just of a dollar per unit, the mChip would be far cheaper to administer than current lab-based tests and because it can scan for multiple proteins, each corresponding to a disease, at the same time with a single blood sample, it is probably even cheaper — and more accurate — than strips which work like store-bought pregnancy tests.
The mChip, by contrast, allows for measurement using a hundred-dollar handheld instrument no more complicated to use than a cell phoneand importantly the mChip produces results in minutes rather than days or weeks, a time saving that can make a big difference in treatment outcome.
The mChip contains a microchip housed inside an injection-moulded plastic casing, explained Vincent Linder, Chief Technological Officer at Claros Diagnostics, which owns or has licensed relevant patents. Unique disease “biomarkers” contained in a pinprick blood sample bind to one of up to 10 individual detection zones.
A nano-scale gold “reagent” which detects a substance via a chemical reaction — is injected, followed by a silver one that interacts with the gold to produce an ultra thin film.
In Rwanda, Sia and colleagues tested the device in Muhima Hospital in Kigali, where on-site results take days or weeks because samples must be sent to an outside laboratory. From a total of 70 specimens with known HIV status, half male and half female, only one tested false, a result that rivals the accuracy of lab-based HIV analysis.
Similar tests on more than 100 archived specimens yielded equally reliable results as did further trials based on samples from female sex workers known to be infected with both HIV and syphilis.
More news will be made available as results are published.