Follow Us:
Sunday, August 01, 2021

Explained: The new and quicker Covid-19 tests approved under the US RADx scheme

Covid-19 testing types, process: While one test uses the gene-editing technique called CRISPR to spot SARS-CoV-2, another uses a technique for scanning the genetic code to see if someone has contracted the virus.

Written by Abhishek De , Edited by Explained Desk | New Delhi |
Updated: August 5, 2020 9:45:10 am
Covid-19 testing types, process: A member of the Brooklyn Hospital Center COVID-19 testing team calls in the next patient in line in the Brooklyn borough of New York (AP)

With experts predicting the demand for Covid-19 tests in the US to be millions more per day above current levels in the coming weeks, the government has awarded contracts worth $248.7 million to seven biomedical firms to produce next-generation tests under its Rapid Acceleration of Diagnostics (RADx) initiative.

The aim behind the initiative is to significantly increase the number, type and availability of tests by millions per week by fall. According to the National Institutes of Health (NIH), the seven firms have already received Emergency Use Authorisation from the US Food and Drug Authority (FDA) after they were found successful in the first phase of trials.

While one test uses the gene-editing technique called CRISPR to spot SARS-CoV-2, another uses a technique for scanning the genetic code to see if someone has contracted the virus. Another uses saliva samples rather than time-consuming swab tests while a fourth uses a hand-held device that produces results within 30 minutes.

The development comes even as the US reported the biggest number of new cases of any month in July since the pandemic began, with more than 1.9 million new cases, according to data from Johns Hopkins University.

What is the RADx initiative?

The NIH launched the RADx programme on April 29 days after receiving an emergency appropriation of $1.5 billion from Congress to support innovative technologies to make millions of rapid Covid-19 tests. The seven firms were chosen from over 650 applicants and 31 projects.

What is the aim of the RADx initiative?

While the US has conducted more Covid-19 tests than any other country, more than 60 million, there have been reports that Americans still continue to wait in queues to get tested and results get delayed by weeks. The RADx initiative will help develop new tests that will allow students, teachers and other workers to get tested frequently, allowing the safe re-opening of educational institutions and bringing back normal economic activity. The initiative is aiming at approximately 6 million daily tests in the United States by December.

What are the new types of Covid-19 tests that have been approved?

Point-of-Care Covid-19 tests

Mesa Biotech: The company has developed a test that employs a hand-held RT-PCR device and a compact, single-use cartridge that detects viral RNA at the point of care. Named Accula SARS-CoV-2 test, one can see the results from the removable cartridge in 30 minutes.

Quidel: This is also a point-of-care test and has been identified for use in nursing homes or pharmacies. Named Quidel Sofia SARS Antigen FIA test, a lateral flow immunoassay, it uses analysers equipped with advanced fluorescence detection with an ultraviolet LED energy source. The analysers give results within 15 minutes.

Talis Biomedical: Capable of returning a result under 30 minutes, the Talis One Covid-19 test uses a multiplexed cartridge to detect SARS-CoV-2 through isothermal amplification of viral RNA and an optical detection system.

📣 Express Explained is now on Telegram. Click here to join our channel (@ieexplained) and stay updated with the latest

Lab-based Covid-19 tests

Ginkgo Bioworks: The Boston-based firm uses next-generation sequencing technologies to process tens of thousands of individual tests at once and will provide end-to-end sample collection and report results within 24-48 hours. The company is expected scale up to 50,000 tests per day in September and 100,000 per day by the end of the year.

Helix OpCo: The Covid-19 test by Helix uses nasal swabs to collect samples that can be processed in very volumes at once and can give results within 24-48 hours using a combination of sophisticated automation processes.

Fluidigm: The California-based firm has developed a diagnostic molecular test integrated with fluidic chips that detects SARS-CoV-2 from saliva specimens. The high-throughput test, named Advanta Dx SARS-CoV-2 RT-PCR Assay, does not need a viral RNA extraction kit.

Mammoth Biosciences Inc: The Covid-19 test, named SARS-CoV-2 DETECTR assay, uses gene-editing CRISPR technology, which provides a simpler workflow and faster turnaround time compared to conventional PCR tests.

The CRISPR technology can detect even a small extract of SARS-CoV-2 genetic material in a nose, mouth or throat swab, or in fluid from the lungs. If the virus’s genetic material is detected, the CRISPR enzyme generates a fluorescent glow.

📣 The Indian Express is now on Telegram. Click here to join our channel (@indianexpress) and stay updated with the latest headlines

For all the latest Explained News, download Indian Express App.

  • The Indian Express website has been rated GREEN for its credibility and trustworthiness by Newsguard, a global service that rates news sources for their journalistic standards.
0 Comment(s) *
* The moderation of comments is automated and not cleared manually by