Scientists at Tulane University have reported a new COVID-19 saliva test that uses a smartphone to provide results in as little as 15 minutes. Similar to technology from UC Berkeley that we reported on last week, the new test uses CRISPR technology and does not involve polymerase chain reaction (PCR) that, though accurate, is slow to deliver results. It is purportedly faster, more accurate, and easier to perform that existing gold standard PCR tests, while requiring less equipment and achieving results in minutes rather than days.
The new test detects RNA from the SARS-CoV-2 virus by relying on CRISPR to amplify the signal. The test involves mixing the assay solution with a sample of patient saliva on a special chip, which then heats and amplifies a specific region of the virus’s RNA. According to a Tulane announcement, “A modified CRISPR complex that contains a ‘guide’ RNA specific for this virus RNA region rapidly binds and cuts both this amplified RNA region and a tagged DNA probe to produce a fluorescent signal that is read by the smartphone device.”
“This test addresses the critical needs for a rapid, ultrasensitive COVID-19 diagnosis along with effective large-scale screening efforts,” added Tony Hu, PhD, corresponding author of the study, in a press release. “Our development can quickly identify patients who have the virus, which is required to help address the ongoing threat to public health worldwide. The sensitivity and simplicity of this test, its straightforward sample collection procedure, and the inexpensive nature of the readout device should permit the rapid translation of this approach to COVID-19 testing efforts once we obtain FDA approval.”
Study in Science Advances: A smartphone-read ultrasensitive and quantitative saliva test for COVID-19
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