Scientists have developed a fascinating technology for a CRISPR (clustered regularly interspaced short palindromic repeats) based COVID-19 diagnostic test utilising the smartphone camera to provide accurate results in under 30 minutes. The novel diagnosis will not only generate a result but also measure the viral load in a given sample. As of now a mobile phone user can see the status of COVID-19 patients around them using a mobile application called Aarogya Setu.
So far the CRISPR diagnostics requires the viral RNA be converted to DNA and amplified before it can be detected, adding time and complexity to the final diagnosis, the researchers said. On contrast, this new method skips the conversion and amplification steps, using CRISPR to directly detect the viral RNA, they said. “One reason we are excited about CRISPR-based diagnostics is the potential for quick, accurate results at the point of need,” said Jennifer Doudna, a senior investigator at Gladstone Institutes in the US.
Doudna is the 2020 Nobel Prize in Chemistry winner for co-discovering CRISPR-Cas genome editing, the technology that underlies this work. Method of working is the Cas13 protein is combined with a reporter molecule that becomes fluorescent when cut, and then mixed with a patient sample from a nasal swab, the researchers said. The sample is then placed in a device attached to a smartphone. If the sample contains RNA from SARS-CoV-2, Cas13 will be activated and will cut the reporter molecule, causing the emission of a fluorescent signal, they said. The smartphone camera acts as a microscope detects the fluorescence and report that a swab tested positive for the virus, according to the researchers.