The slide, developed at Imperial College London and known as TriSilix, is a ‘micro-laboratory’ that performs a miniature version of the polymerase chain reaction (PCR) on site. PCR is the gold standard test for detecting viruses and bacteria in biological samples such as body fluids, feces or environmental samples.
Although PCR is usually performed in a laboratory, which means that test results are not immediately available, this new laboratory can process and present the results on a slide within minutes.
The chip is made of silicone, the same material used to make electronic chips. Silicone itself is cheap, but it is expensive to process into chips that require massive, ‘extremely clean’ factories, also known as clean rooms. To make the new lab-on-chip, the researchers developed a series of methods to manufacture the chips in a standard laboratory, reducing the cost and time it takes to manufacture, making it possible to manufacture anywhere to manufacture the world.
The principal investigator, dr. Firat Guder, of Imperial’s Bioengineering Department, said: “Instead of sending swabs to the lab or going to a clinic, the lab can come to you with a fingernail-sized chip. test used just like the way people with diabetes use blood sugar tests, by giving a sample and waiting for results – except this time for infectious diseases. ‘
The paper will be published today (2 December 2020) Nature communication.
The researchers have so far used TriSilix to treat a bacterial infection that mainly occurs in animals, as well as a synthetic version of the genetic material of EARS-CoV-2, the virus behind COVID-19.
According to the researchers, the system can now be mounted on devices for testing the blood sugar test. This will allow people to test themselves and get home results for colds, flu, recurrent urinary tract infections (UTIs) and COVID-19.
There are already table devices for testing infections such as COVID-19, but these tests can be time consuming and expensive because the patient has to go to a clinic, take a sample through a healthcare professional and go home or in the clinic must keep waiting. People who leave their homes when they are not feeling well increase the risk of a pathogen spreading to others.
If validated on human samples, the results can yield results outside the clinic, at home, or on the go within minutes.
The researchers also say that a highly portable test can speed up the diagnosis of infections and reduce costs by eliminating the transport of samples. Such tests can be performed by citizens in the absence of highly trained medical professionals. So if they have to isolate themselves, they can start immediately without possibly infecting others.
Testing more accessible and cheaper is especially important for people in rural areas of low-income countries, where clinics can be far and expensive to travel to. If made available to patients, it can also be used to diagnose and monitor infections such as UTIs, which often occur despite antibiotics.
First author Dr Estefania Nunez-Bajo, also from the Department of Bioengineering, said: “Monitoring infections at home can even help patients, with the help of their doctor, personalize and adapt their use of antibiotics to the reduce growing problem of antibiotics. resistance. ”
Each lab-on-a-slide contains a DNA sensor, temperature detector and heater to automate the testing process. A typical smartphone battery can deliver up to 35 tests on a single charge.
Next, the researchers plan to validate their chips with clinical samples, automate sample preparation, and advance their commercial electronics. They are looking for partners and funders to speed up the translation of technology to deliver tests on limited resource institutions at homes, farms or remote locations in the developing world.
Reference: “Disposable all-in-one micro-qPCR based on silicon for rapid detection of pathogens on the premises” by Estefania Nunez-Bajo, Alexander Silva Pinto Collins, Michael Kasimatis, Yasin Cotur, Tarek Asfour, Ugur Tanriverdi, Max Grell, Matti Kaisti, Guglielmo Senesi, Karen Stevenson and Firat Güder, December 2, 2020, Nature communication.
DOI: 10.1038 / s41467-020-19911-6