SARS-CoV-2

How the SARS-CoV-2 Coronavirus Enters Host Cells and How To Block It

Posted on by Johanna Lee
TE micrograph of a single MERS-CoV
Photo courtesy of National Institute of Allergy and Infectious Diseases

In December 2019, a new disease emerged from a seafood market in Wuhan, China. People who were infected began experiencing fever, dry cough, muscle aches and shortness of breath. The disease swept through China like wildfire and quickly spread overseas to almost every continent. We now know the virus that caused this disease, SARS-CoV-2, is a member of the severe acute respiratory syndrome coronavirus, and the disease itself was officially named COVID-19. According to the Johns Hopkins University Coronavirus Resource Center, there are 877,422 confirmed cases of COVID-19 worldwide, and 43,537 total deaths at the publication of this blog. Those numbers are only expected to increase over the next few weeks.

In this moment of crisis, scientists all around the world are desperately trying to find ways to treat and prevent the disease. One strategy for preventing the spread of the virus is to block its entry into human cells. But first we need to understand how SARS-CoV-2 enters human cells. A research group at the German Primate Center led by Dr. Stefan Pohlmann provides some answers in a recent publication in Cell.

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RNA Extraction for Clinical Testing—Do Not Try this with Home-brew

Posted on by Michele Arduengo

This blog was written with much guidance from Jennifer Romanin, Senior Director IVD Operations and Global Service and Support, and Ron Wheeler, Senior Director, Quality Assurance and Regulatory Affairs at Promega.

A Trip Down Memory Lane

Back in the day when we all walked two miles uphill in the snow to get to our laboratories, RNA and DNA extraction were home-brew experiences. You made your own buffers, prepped your own columns and spent hours lysing cells, centrifuging samples, and collecting that fluorescing, ethidium bromide-stained band of RNA in the dark room from a tube suspended over a UV box. Just like master beer brewers tweak their protocols to produce better brews, you could tweak your methodology and become a “master isolater” of RNA. You might get mostly consistent results, but there was no guarantee that your protocol would work as well in the hands of a novice.

Enter the biotechnology companies with RNA and DNA isolation kits—kits and columns manufactured under highly controlled conditions delivering higher quality and reproducibility than your home-brew method. These systems have enabled us to design ever more sensitive downstream assays–assays that rely on high-quality input DNA and RNA, like RT-qPCR assays that can detect the presence of a specific RNA molecule on a swab containing only a few hundred cells. With these assays, contaminants from a home-brew isolation could result in false positives or false negatives or simply confused results. Reagents manufactured with pre-approved standard protocols in a highly controlled environment are critical for ultra sensitive tests and assays like the ones used to detect SARS-CoV-2 (the virus that causes COVID-19).

The Science of Manufacturing Tools for Scientists

There are several criteria that must be met if you are producing systems that will be sent to different laboratories, used by different people with variable skill sets, yet yield results that can be compared from lab to lab.

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Testing for COVID-19: How it Works

Posted on by Kari Kenefick

Depending on your viewpoint, source of information and tolerance for risk, this can be a frightening time for persons all over the planet. The level of disruption to daily life that we’re all experiencing due to COVID-19 is unprecedented.

We are all either not working, working from home and away from our normal offices, or in some cases working many more hours to cover for sick coworkers and caring for SARS-CoV-2-infected persons.

But there is good news if you find that information is power. We hope that some information about the testing being used in the US for this novel coronavirus might be fuel for you, empowering in terms of information.

What is the Name of the Virus, and the Disease?
Since this is a global pandemic, the World Health Organization was instrumental in naming the virus and disease. From this web page: the disease is called COVID-19.

The coronavirus responsible for this disease is SARS-CoV-2.

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Investigation of Remdesivir as a Possible Treatment for SARS-CoV-2 (2019-nCoV)

Posted on by Kyle Hooper

Remdesivir (RDV or GS-5734) was used in the treatment of the first case of the SARS-CoV-2 (formerly 2019-nCoV ) in the United States (1). RDV is not an approved drug in any country but has been requested by a number of agencies worldwide to help combat the SARS-CoV-2 virus (2). RDV is an adenine nucleotide monophosphate analog demonstrated to inhibit Ebola virus replication (3). RDV is bioactivated to the triphosphate form within cells and acts as an alternative substrate for the replication-necessary RNA dependent RNA polymerase (RdRp). Incorporation of the analog results in early termination of the primer extension product resulting in the inhibition.

Note the spikes that adorn the outer surface of the virus, which impart the look of a corona surrounding the virion, when viewed electron microscopically. In this view, the protein particles E, S, M, and HE, also located on the outer surface of the particle, have all been labeled as well. A novel coronavirus virus was identified as the cause of an outbreak of respiratory illness first detected in Wuhan, China in 2019.
This illustration, created at the Centers for Disease Control and Prevention (CDC), reveals ultrastructural morphology exhibited by coronaviruses. Photo Credit: Alissa Eckert, MS; Dan Higgins, MAM CDC

Why all the interest in RDV as a treatment for SARS-CoV-2 ? Much of the interest in RDV is due to a series of studies performed by collaborating groups at the University of North Carolina Chapel Hill (Ralph S. Baric’s lab) and Vanderbilit University Medical Center (Mark R. Denison’s lab) in collaboration with Gilead Sciences. 

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