Getting Back to the Bench

Today’s blog is written by Technical Services Scientist, Joliene Lindholm, PhD.

Many of us have come back to the lab after a summer of field work or a vacation break, but there is usually someone checking in on the lab to make sure the gel electrophoresis box did not completely overflow with dead bugs and the water baths are not completely overrun with exciting new algae. Maybe this was just because I worked in an older building in an entomology department, but why do insects like running buffer so much? Some labs have been completely shut down for months at this point or maybe just a few essential people have been in keeping stocks and colonies going. Some labs have adapted to the new normal and developed guidelines to keep researchers safe while still doing essential work in the lab. See how the Promega Scientific Applications group has maintained this balance.

Headed back to the lab bench? Take some time to make sure you have everything you need to start up your research projects.

Here are a few tips from what I learned in managing a lab after a period of field work to get back into the swing of things:

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Choices for Measuring Luciferase-Tagged Reporter Pseudotyped Viral Particles in Coronavirus Research

Coronavirus (CoV) researchers are working quickly to understand the entry of SARS-CoV-2 into cells. The Spike or S proteins on the surface of a CoV is trimer. The monomer is composed of an S1 and S2 domain. The division of S1 and S2 happens in the virus producing cell through a furin cleavage site between the two domains. The trimer binds to cell surface proteins. In the case of the SARS-CoV, the receptor is angiotensin converting enzyme 2. (ACE2). The MERS-CoV utilizes the cell-surface dipeptidyl peptidase IV protein. SARS-CoV-2 uses ACE2 as well. Internalized S protein goes though a second cleavage by a host cell protease, near the S1/S2 cleavage site called S2′, which leads to a drastic change in conformation thought to facilitate membrane fusion and entry of the virus into the cell (1).  

CDC / Alissa Eckert, MS; Dan Higgins, MAMS

Rather than work directly with the virus, researchers have chosen to make pseudotyped viral particles. Pseudotyped viral particles contain the envelope proteins of a well-known parent virus (e.g., vesicular stomatitis virus) with the native host cell binding protein (e.g., glycoprotein G) exchanged for the host cell binding protein (S protein) of the virus under investigation. The pseudotyped viral particle typically carries a reporter plasmid, most commonly firefly luciferase (FLuc), with the necessary genetic elements to be packaged in the particle. 

To create the pseudotyped viral particle, plasmids or RNA alone are transfected into cells and the pseudotyped viruses work their way through the endoplasmic reticulum and golgi to bud from the cells into the culture medium. The pseudoviruses are used to study the process of viral entry via the exchanged protein from the virus of interest. Entry is monitored through assay of the reporter. The reporter could be a luciferase or a fluorescent protein.   

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38 Years After First Release, RNasin Protects COVID-19 Tests

A protein first purified and sold by Promega almost four decades ago has emerged as a crucial tool in many COVID-19 testing workflows. RNasin® Ribonuclease Inhibitor was first released in 1982, only four years after the company was started. At that time, the entire Promega catalog fit on a single sheet of 8.5 × 11” paper, and RNasin was one of the first products to draw widespread attention to Promega. Today, the demand for this foundational product has skyrocketed as it supports labs responding to the COVID-19 pandemic.

What is RNasin® Ribonuclease Inhibitor?

RNA is notoriously vulnerable to contamination by RNases. These enzymes degrade RNA by breaking the phosphodiester bonds forming the backbone of the molecule. To say that RNases are everywhere is barely an exaggeration – almost every known organism produces some form of RNase, and they’re commonly found in all kinds of biological samples. They’re easily introduced into experimental systems, since even human skin secretes a form of RNase. Once they’re present, it’s very hard to get rid of them. Even an autoclave can’t inactivate RNases; the enzymes will refold and retain much of their original activity.

RNasin® Ribonuclease Inhibitor is a protein that has been shown to inhibit many common contaminating RNases, but without disrupting the activity of enzymes like reverse transcriptase that may be essential to an experiment. It works by binding to the RNase enzyme, prevent it from acting on RNA molecules. This is important for ensuring that RNA samples are intact before performing a complex assay.

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Working from Home: Finding Productivity in this New Normal

During this time of adjusting to a new normal, one of the most difficult things that I have had to get used to is being productive in my own home. Work from home (WFH) days are embraced by some people and not by others. For me, transitioning from working in an office and school setting, to working at-home and completing online courses, has led me on a search for answers about how to get the most out of my day. After creating a productive at-home work environment for me, I wanted to share some of my findings with you.

Here are some of the tips that I have found useful:

Section out a portion of your home for work only.

When I first started working from home, I moved room to room working wherever I felt most comfortable. I soon found this affected my organization and time management, so I started keeping all my work in one area. Now, as I sit here writing this post, I know where all of my work is, and I also know that when I walk out of this area I can ‘power down’ my mind knowing I no longer have to do work.

Power off your electronics when not working.

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Neutralizing Antibodies to SARS-CoV-2 Shown to Lessen Infection in Mice

Here in the US, as around the world, we’re beginning to come out of COVID-19 hiding, whether mandated or voluntary. We are slowly starting to leave the confines of home and “safer at home” orders. Many of us are donning masks and venturing out as needed, still under social distancing considerations.

We’re looking forward to a time when social distancing won’t be necessary, when we can see our relatives and friends, and give them a hug without concern for their safety or ours.

When will that time come? Many believe that it won’t be completely safe until there is an effective vaccine to protect us from SARS-CoV-2.

How does a vaccine protect us? Effective vaccines cause our immune system to produce antibodies that are specific for SARS-CoV-2, so that if we come into contact with the virus, it will be neutralized, preventing infection.

At this time, many questions remain about whether SARS-CoV-2 virus causes production of antibodies. And if antibodies are produced, are they protective?

In some exciting news this week, scientists studying SARS-CoV-2 have shown that neutralizing antibodies to this virus are made in humans. Here’s a look at their work.

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Antibody From Humanized Mice Blocks SARS-CoV-2 Infection in Cells

As the SARS-CoV-2 coronavirus continues to spread throughout the world, the race is on to produce antivirals and vaccines to treat and prevent COVID-19. One potential treatment is the use of human monoclonal antibodies, which are antibodies engineered to target and block specific antigens. A recent study by Wang, C. and colleagues published in Nature Communications showed that human monoclonal antibodies can be used to block SARS-CoV-2 from infecting cells.

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A Specific & Sensitive Matter: The Trouble with COVID-19 Antibody Tests

From the beginning of this pandemic, scientists around the world have been working around the clock in pursuit of answers that can effectively combat the SARS-CoV-2 virus. One of hardest things for people to grapple with, is all the unknowns: When will this end? When can I safely visit my friends and family again? What if I have it or had it and I don’t even know it?  

The increased availability of serological testing has helped ease people’s minds about their personal COVID-19 status. From a distance, serological testing may seem like a huge milestone in the marathon that is this pandemic. Unfortunately, many of these tests provide murky and inconsistent results.

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RiboMAX and the Effort to Find Antiviral Drugs to Fight Coronaviruses and Enteroviruses

Prior to 2020, there were two major outbreaks of coronaviruses. In 2003, an outbreak of SARS-CoV sickened 8098 people and killed 774. In 2012, an outbreak of MERS-CoV began which so far has sickened 2553 and killed 876. Although the overall number of MERS cases is low, the disease has a high fatality rate, and new cases are still being reported. Even though fatality rates are high for these two outbreaks, containment was quickly achieved. This makes development of a treatment not commercially viable so no one had undertaken a large effort to develop an approved treatment for either coronavirus infection.

Fast forward to late 2019/2020… well, you know what has happened. There is currently no reliable antiviral treatment for SARS-CoV-2, the coronavirus that causes COVID-19 infections.

Zhang, et al. thought of a way to make an antiviral treatment commercially viable. If the treatment is actually a broad-spectrum antiviral, it could be used to treat more than one infection, meaning, it can be used to treat more people and thus be seen as more valuable and worth the financial risk to pharmaceutical companies. So, they decided to look at the similarities between coronaviruses and enteroviruses.

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Public-Private Initiative to Increase COVID-19 Testing Capacity by Using Promega Maxwell Instrument in India

This blog is written by guest blogger, Dr Rajnish Bharti, General Manager of Promega Biotech India Pvt Ltd.

As COVID-19 cases accelerate, the country of India has decided to scale up testing capacity to 100,000 tests per day in the coming days.

In a major step to counter the coronavirus crisis, Promega India is supporting government agencies through our automated instruments. The Maxwell® RSC instrument is a compact, automated RNA extraction platform that processes up to 48 samples simultaneously in less than 35 minutes. The automated Promega solution allows laboratories to process up to 400 samples in a typical 8-hour shift.

Scientists in India train on the Maxwell RSC 48
Forensic Science Laboratory-Jaipur and SMS Hospital Jaipur join hands together to use Promega Maxwell® RSC 48 to Increase COVID-19 Testing capacity.
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Getting a PhD in Sweatpants: Guest Blog by Dr. Susanna Harris

Today’s blog is guest-written by Susanna Harris, who recently defended her PhD thesis at the University of North Carolina in Chapel Hill.


I just defended my PhD. Nearly six years of blood, sweat, and tears, most of which were cleaned up with Kimwipes while sitting at my desk in a laboratory facing out towards the UNC Chapel Hill football field. Nearly six years of work, all summed up in a handful of slides. Nearly six years of work, explained to my friends, family, and colleagues – a moment I had dreamed of since the fall of 2014.

What I hadn’t dreamed of? That I would be sitting at my small desk in the corner of my room, with no present audience aside from my snoring dogs. That there would be no dinner celebration that carried into a night of fun along Franklin Street. That, unseen by the viewers of my defense, I would be wearing sweatpants as my name changed from Ms. to Dr. Harris.

Pictured: The audience for Susanna’s thesis defense.

Why did I wear sweatpants when I could have worn literally anything in my closet? Because I think it’s hilarious. I believe this situation will end and we will walk away with memories and lessons learned from an extremely difficult time in the history of the world. I want to walk away with one more ridiculous story to add to a long list of “What even was that?” tales from grad school.

Working towards a PhD is hard at any time; let’s not pretend this pandemic isn’t making things even worse. I was fortunate in many ways that my advisor had already moved our laboratory to a new state in 2019, allowing me to adjust to meeting through webcams and working from home before the pandemic changed the lives of all North Carolinians. This has given me a unique perspective to tease out which problems come from distance working and which are the result of Safer-At-Home orders. Based on my experiences, here are a few tips, tricks, and words of warning.

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