Hospitals Testing Fast Covid-19 Diagnostic

Scanning electron microscope image of SARS-Cov-2 virus, in orange, emerging from cells (NIAID, Flickr)

12 Aug. 2020. A New England hospital system is assessing with real patients a point-of-care test for Covid-19 viruses that returns results in about an hour. Dartmouth-Hitchcock Health, a health care provider and hospital chain in New Hampshire and Vermont is evaluating Covid-19 test kits made by Sherlock Biosciences in Cambridge, Massachusetts.

The U.S. has an urgent need to expand screening and testing for Covid-19 infections to bring the pandemic under control. Most Covid-19 tests today use the so-called gold standard reverse transcription-polymerase chain reaction, or RT-PCR, testing to identify SARS-CoV-2 viral genetic material in nasal swabs or other specimen samples. For the vast majority of these tests, samples are sent to remote labs for analysis, causing long backlogs and delays stretching into weeks to get results.

“RT-PCR tests have been a mainstay in testing for the global Covid-19 pandemic in the U.S.,” says pathologist Gregory Tsongalis, director of clinical genomics at Dartmouth-Hitchcock Health, in a Sherlock Biosciences statement. “Unfortunately, the sheer volume of tests demanded by the pandemic, coupled with the dwindling supply of reagents and other consumables needed to conduct RT-PCR, has created a dire need for alternative testing methods.”

Sherlock Biosciences develops diagnostic tests using Crispr, short for clustered regularly interspaced short palindromic repeats. Crispr is a genome-editing process based on bacterial defense mechanisms that use RNA to identify and monitor precise locations in DNA. Sherlock, short for specific high-sensitivity enzymatic reporter unlocking, employs Crispr to edit RNA rather than DNA.

The Sherlock technology, first developed at research labs affiliated with Harvard University and MIT, uses Crispr editing enzymes that seek out specific genetic sequences in a specimen sample, and if detected in the sample, bind to and cut the RNA in nearby locations. Sherlock adds a reporter sequence to the RNA, a specific piece of synthetic RNA, which also gets cut by the editing enzyme, releasing a signal identifying the presence of the original target sequence. When coupled with a companion technique (and acronym) Inspectr, short for internal splint-pairing expression cassette translation reaction, reporter sequence signals are converted into a bioluminescent visual display that can appear on an everyday material like paper and at room temperature.

As reported in Science & Enterprise in May, Sherlock Biosciences and labs at MIT and associated research institutes developed a prototype Covid-19 test kit with the Sherlock technology. Less than a week later, the test kit received an emergency use authorization from FDA. In July, Sherlock Biosciences and medical test device maker binx health — the company name is spelled in all lower-case — joined forces to develop a high-speed Covid-19 point-of-care test kit for doctors’ offices, retail store clinics, long-term care facilities, and other institutions.

The new agreement with Dartmouth-Hitchcock Health aims to produce real-world evidence with Sherlock’s Covid-19 point-of-care test. “Ultimately,” notes William Blake, Sherlock’s chief technology officer, “the measure of success for any diagnostic is how it performs in the hands of real customers with real patient samples.”

More from Science & Enterprise:

• Breath Analysis Sensor Licensed to Detect Covid-19
• NIH Issues Contracts for Faster Covid-19 Diagnostics
• Trial Testing Point-of-Care Covid-19 Diagnostic
• NIH Expands Covid-19 Test Technology Challenge
• Single Sensor to Detect Covid-19, Flu in Works

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