Multistage lateral flow devices perform advanced testing


Georgia Tech researchers have developed a lateral flow testing platform that can perform advanced tests that would otherwise require a lab. By controlling liquid flow through the lateral flow test, the research team designed it so that it can perform advanced multi-step tests that do not require sophisticated laboratory equipment and significant time periods. To date, they have designed advanced test strip tests that can detect both COVID-19 and influenza simultaneously, and others that can perform immunoassays to detect Zika virus, HIV, hepatitis B virus, or malaria.

Lateral flow tests, also known as test strip tests, are a very convenient way to perform biological measurements almost anywhere. The most widely used lateral flow assay is the ubiquitous pregnancy test, and during the COVID-19 pandemic lateral flow antigen tests have been used as a rapid assessment of COVID status in many countries. .

Lateral flow technology is very easy to use, and requires the user to add a few drops of their sample to one end of the device (or immerse it in a sample), and this liquid flows through a matrix due to capillary action, and usually visually shows results in 15-30 minutes. While the technology is convenient and fast, so far, the types of tests that lateral flow devices can perform have been limited. Advanced assays that require multiple steps that are performed at specific times, with different incubation periods in between, often exceed the capabilities of this technology.

“These tests have been very popular for years, mainly because they are very easy to use. Do not send anything to the lab or clinic because these tests do not require any external equipment to operate. This is an advantage,” said Fatih Sarioglu. researcher involved in the study, in a Georgia Tech ad. “But there is also a disadvantage. There are limitations to what they can do. “

To further advance the technology and allow multi-step testing, the researchers used water-insoluble ink to introduce “obstacles” that help control hair flow through the device, creating “timers” that hold the liquid in certain points for a specific time.

“By strategically printing these timers, we can schedule trials to coordinate different hair flows,” Sarioglu said. “This allows us to introduce multiple liquids and chemical reactions of several steps, with optimal incubation times, so that we can perform complex and automated tests that otherwise would normally have to be performed in laboratories. This takes us further. of conventional lateral flow tests “.

Study a Advances in Science: Capillary flow control in lateral flow tests using delaminator timers

Study a ACS Sens: Point-of-care toolkit for multiple molecular diagnosis of SARS-CoV-2 viruses and influenza A and B

Via: Georgia Technology

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