Have No Fear, qPCR Is Here: How qPCR can help identify food contamination

Foodborne disease affects almost 1 in 10 people around the world annually, and continuously presents a serious public health issue (9).

Food Contamination-Strawberries-Blueberries-Magnifying glass
Food Contamination is common and can be seen in a variety of forms and food products.

More than 200 diseases have evolved from consuming food contaminated by bacteria, viruses, parasites, and chemical substances, resulting in extensive increases in global disease and mortality rates (9). With this, foodborne pathogens cause a major strain on health-care systems; as these diseases induce a variety of different illnesses characterized by a multitude of symptoms including gastrointestinal, neurological, gynecological, and immunological (9,2).

But why is food contamination increasing?

New challenges, in addition to established food contamination hazards, only serve to compound and increase food contamination risks. Food is vulnerable to contamination at any point between farm and table—during production, processing, delivery, or preparation. Here are a few possible causes of contamination at each point in the chain (2):

  • Production: Infected animal biproducts, acquired toxins from predation and consumption of other sick animals, or pollutants of water, soil, and/or air.
  • Processing: Contaminated water for cleaning or ice. Germs on animals or on the production line.
  • Delivery: Bacterial growth due to uncontrolled temperatures or unclean mode of transport.
  • Preparation: Raw food contamination, cross-contamination, unclean work environments, or sick people near food.

Further emerging challenges include, more complex food movement, a consequence of changes in production and supply of imported food and international trade. This generates more contamination opportunities and transports infected products to other countries and consumers. Conjointly, changes in consumer preferences, and emerging bacteria, toxins, and antimicrobial resistance evolve, and are constantly changing the game for food contamination (1,9).

Hence, versatile tests that can identify foodborne illnesses in a rapid, versatile, and reliable way, are top priority.

Continue reading “Have No Fear, qPCR Is Here: How qPCR can help identify food contamination”

What We Know About the COVID-19 and the SARS-CoV-2 Virus

David Goodsell image of SARS-2-CoV
Image by David Goodsell

In the nine months since the first cases of COVID-19 were noticed in Wuhan, China, the virus has spread around the globe and infected over 22 million people. As with all emerging infectious diseases, we often find ourselves with more questions than answers. However, through the tireless work of researchers, doctors and public health officials worldwide, we have learned a lot about the virus, how it spreads and how to contain it.

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Emergency Use Authorization: The What, the Why and the How

This blog is written by guest blogger, Heather Tomlinson, Director of Clinical Diagnostics at Promega.

Finding safe and effective treatments for human diseases takes time.  Medication and diagnostic tests can take decades to discover, develop and prove safe and effective.  In the United States, the FDA stands as the gold-standard gatekeeper to ensure that treatments and tests are reliable and safe. The time we wait in review and clearance means less risk of ineffective or unsafe treatments.

And yet, in a pandemic, we are behind before we even start the race to develop diagnostic tests, so critical for understanding how an infectious disease is spreading. That is when processes like the FDA’s fast track of Emergency Use Authorization (EUA) are critical. Such authorization allows scientists and clinicians to be nimble and provide the best possible test protocol as quickly as possible, with the understanding that these protocols will continue to be evaluated and improved as new information becomes available. The EUA focuses resources and accelerates reviews that keep science at the fore and gets us our best chance at staying safe and healing.

The Maxwell 48 RSC Instrument and the Maxwell RSC Total Viral Nucleic Acid Isolation Kit are now listed as options within the CDC EUA protocol.

For scientists working around the clock, the FDA’s EUA process is ready to review and respond. Getting an EUA  gives clinical labs a very specific and tested resource to guide them to the tools and tests to use in a crisis.

Typically the Centers for Disease Control (CDC) will develop the first test or protocol that receives FDA EUA in response to a crisis like a pandemic.  For COVID-19 the CDC 2019-Novel Coronavirus Real-Time RT-PCR Diagnostic Panel received FDA EUA clearance in early February. This is the test protocol used by the public health labs that work with the CDC and test manufacturers around the world.

Throughout a crisis such as the current pandemic, scientists continually work to improve the testing protocols and add options to the EUA protocols. This enables more flexibility in the test protocols. Promega is fortunate to play a part of the CDC EUA equation for diagnostic testing. Our GoTaq® Probe 1-Step PRT-qPCR System is one of a few approved options for master mixes in the  CDC qPCR diagnostic test,  and now our medium-throughput Maxwell 48 Instrument and Maxwell Viral Total Nucleic Acid Purification Kit  have been added to the CDC protocol as an option for the RNA isolation step as well. These additions to the CDC EUA means that laboratories have more resources at their disposal for the diagnostic testing which is so critical to effective pandemic response.

The Emergency Use Authorization provides the FDA guidance to strengthen our nation’s public health during emergencies, such as the current COVID-19 pandemic. The EUA allows continual improvement of an authorized protocol through the collaborative efforts scientists in all academia, government and industry to identify and qualify the most reliable technologies and systems, giving labs more flexibility as new products are added as options.

Dr. Tomlinson is the Director for the Global Clinical Diagnostics Strategic Business Unit at Promega Corporation with over 15 years of experience in clinical diagnostic test development. She is responsible for leading the team that drives strategy in the clinical market for Promega. Her background is in infectious disease diagnostic testing, with a focus on HIV drug resistance and evolution.  Her recent work has been in oncology companion diagnostic test development.  Heather has is an accomplished international presenter, delivering conference presentations in the United States, Europe, Asia, and Africa.

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RT-qPCR and qPCR Assays—Detecting Viruses and Beyond

We have all been hearing a lot about RT-PCR, rRT-PCR and RT-qPCR lately, and for good reason. Real-Time Reverse Transcriptase Polymerase Chain Reaction (rRT-PCR) is the technique used in by the Center for Disease Control (CDC) to test for COVID-19. Real-time RT-PCR, or quantitative RT-PCR (RT-qPCR)*, is a specialized PCR technique that visualizes amplification of the target sequesnce as it happens (in real time) and allows you to measure the amount of starting target material in your reaction. You can read more about the basics of this technique, and watch a webinar here. For more about RT-PCR for COVID-19 testing, read this blog.

Both qPCR and RT-qPCR are powerful tools for scientist to have at their disposal. These fundamental techniques are used to study biological process in a wide range of areas. Over the decades, Promega has supported researchers with RT-qPCR and qPCR reagents and systems to study everything from from diseases like COVID-19 and cancer to viruses in elephants and the circadian rhythm of krill.  

Continue reading “RT-qPCR and qPCR Assays—Detecting Viruses and Beyond”

Researching the Researcher: Abbeah Navasca, 2019 Real-Time PCR Grant Winner

The three winners of the 2019 Real-Time PCR Grants have been hard at work in the six months since receiving their grants. Each winner was eligible to receive up to $10,000 in free PCR reagents as well as the opportunity to collaborate with our knowledgeable technical service and training teams.

Abbeah Navasca is a plant pathology researcher with the Tagum Agricultural Development Company, Inc. (TADECO*, Philippines). She is developing treatments for viral infections that affect one of Philippines’ largest and most valuable agricultural exports: bananas. As a result of the qPCR grant, she and two of her colleagues were able to participate in sample preparation and analysis workshops with Promega Technical Services experts in Singapore. During her visit, the team worked through strategies for plant sample preparation and amplified those samples with the GoTaq® 1-Step RT-qPCR System. We had a chance to ask her more before she headed back to her lab.

Continue reading “Researching the Researcher: Abbeah Navasca, 2019 Real-Time PCR Grant Winner”

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

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. 

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

Researching the Researchers: Alberto Biscontin

2019 Real-Time PCR Grant

The three 2019 Real-Time PCR Grant Winners have been hard at work in the six months since winning their grants. Each winner was eligible to receive up to $10,000 in free PCR reagents as well as the opportunity to collaborate with our knowledgeable technical service and training teams.

One of the 2019 winners, Alberto Biscontin (University of Padova, Italy), performs research in the fields of Neurogenetics and Chronobiology. He is looking to shed greater light on the circadian rhythms of the Antarctic krill. Alberto published his most recent analysis in Nature and GoTaq® qPCR Master Mix helped him validate expression of genes for his study.

His qPCR data showed support for internal mechanisms that not only support daily living but also clarified the overwintering process of the krill. Now that Alberto has sized up some zooplankton, we asked him to share a little more about himself and his research:

Q: How long have you been a researcher?
A: I have been a researcher since 2012.

Q: How did you decide to research Antarctic krill?
A: In 2013, I had the opportunity to join the international Antarctic research program PolarTime. [It] brought together eight research groups with different scientific expertise to study seasonal and daily rhythms in the Antarctic krill Euphausia superba.

Q: When you are not busy at the bench, what do you like to do?
A: Traveling. I love strolling through open-air markets.

Q: Are there any tips or tricks you have learned that make your job easier?
A: You can easily switch from a classic RT-PCR protocol to a cheaper and faster One-step protocol using the same primers and temperatures.

Q: What comes next?
A: I would like to characterize the clock machinery of other polar organisms to understand whether high latitude clocks have developed similar strategies to cope with [the] polar environment. Moreover, a better understanding of marine circadian clocks could help to shed light on the evolution of the animal circadian machinery.

You can find Alberto’s most recent publication in Nature Scientific Reports. The 2020 Real-Time PCR Grant will be coming soon. For more information on the 2019 winners and information on the 2023 Grant, visit the Real-Time Grant web page. Be sure to follow us on social media for the most up-to-date information regarding the 2020 Grant, including application deadlines and winner notifications!

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Nucleic Acid from FFPE Samples: Effects of Pre-Analytical Factors on Downstream Success

Part one of three

Peer-reviewed publications containing data dervived from analysis of nucleic acids isolated from FFPE samples have increased dramatically since 2006.

Formalin Fixed Paraffin Embedded samples (FFPE) have been a mainstay of the pathology lab for over 100 years. Initially FFPE blocks were sectioned, stained with simple dyes and used for studying morphology, but now a variety of biomolecules can be analyzed in these samples. Over the past 10 years we have discovered that there is a treasure trove of genomics data waiting to be unearthed in FFPE tissue. While viral RNAs and miRNA were some of the first molecules found to be present and accessible for analysis starting in the 1990s, improvements to DNA and RNA extraction methods have demonstrated that PCR, qPCR, SNP genotyping, Exome and WGS are possible. This has resulted scientific publications of DNA and RNA data generated from FFPE samples starting in 2006, and today we see immense amounts of data generated from FFPE—with nearly 2000 citations in 2018 reporting sequencing of FFPE samples.

Depending on the type of project, prospective or retrospective, the genomics scientist has an opportunity to affect the probability of success by better understanding the fixation process. The challenge with FFPE is the host of variables that have the potential to negatively affect downstream assays.

Continue reading “Nucleic Acid from FFPE Samples: Effects of Pre-Analytical Factors on Downstream Success”

qPCR: The Very Basics

Real-Time (or quantitative, qPCR) monitors PCR amplification as it happens and allows you to measure starting material in your reaction.
qPCR monitors amplification in real and allows you to measure starting material.

For those of us well versed in traditional, end-point PCR, wrapping our minds and methods around real-time or quantitative (qPCR) can be challenging. Here at Promega Connections, we are beginning a series of blogs designed to explain how qPCR works, things to consider when setting up and performing qPCR experiments, and what to look for in your results.

First, to get our bearings, let’s contrast traditional end-point PCR with qPCR.

End-Point PCRqPCR
Visualizes by agarose gel the amplified product AFTER it is produced (the end-point)Visualizes amplification as it happens (in real time) via a detection instrument
Does not precisely measure the starting DNA or RNAMeasures how many copies of DNA or RNA you started with (quantitative = qPCR)
Less expensive; no special instruments requiredMore expensive; requires special instrumentation
Basic molecular biology techniqueRequires slightly more technical prowess

Quantitative PCR (qPCR) can be used to answer the same experimental questions as traditional end-point PCR: Detecting polymorphisms in DNA, amplifying low-abundance sequences for cloning or analysis, pathogen detection and others. However, the ability to observe amplification in real time and detect the number of copies in the starting material can quantitate gene expression, measure DNA damage, and quantitate viral load in a sample and other applications.

Anytime that you are preforming a reaction where something is copied over and over in an exponential fashion, contaminants are just as likely to be copied as the desired input. Quantitative PCR is subject to the same contamination concerns as end-point PCR, but those concerns are magnified because the technique is so sensitive. Avoiding contamination is paramount for generating qPCR results that you can trust.

  1. Use aerosol-resistant pipette tips, and have designated pipettors and tips for pre- and post-amplification steps.
  2. Wear gloves and change them frequently.
  3. Have designated areas for pre- and post-amplification work.
  4. Use reaction “master mixes” to minimize variability. A master mix is a ready-to-use mixture of your reaction components (excluding primers and sample) that you create for multiple reactions. Because you are pipetting larger volumes to make the reaction master mix, and all of your reactions are getting their components from the same master mix, you are reducing variability from reaction to reaction.
  5. Dispense your primers into aliquots to minimize freeze-thaw cycles and the opportunity to introduce contaminants into a primer stock.

These are very basic tips that are common to both end-point and qPCR, but if you get these right, you are off to a good start no matter what your experimental goals are.

If you are looking for more information regarding qPCR, watch this supplementary video below.

Pack a Little Science into Your Summer with Advanced Courses from BTCI

This new cGMP facility was built to have the least effect on the natural environment as possible--surrounded by rain gardens and native plantings, using grey water for flushing toilets--sustainable growth was the goal.
Summer on the Prairie at Promega–Study science surrounded by birds, bees, flowers and amazing prairie.

Summer, a much-looked forward to season. We typically pack in the activities and make the most of the daylight. We work hard and we play hard.  This summer will be no exception, and at the BTC Institute, we are already getting set to host as many students as we can. We will see middle and high schoolers, K-12 teachers, college students, graduate students, college and university faculty and staff, and professionals in the biotech community under our roof at some point. You may want to join us too!

Our programs for advanced learners, geared toward the graduate student or biotech professional, offer much more than just a rigorous immersion in molecular biology theory and practice. Held at the BTC Institute at Promega Headquarters, they are taught by highly knowledgeable scientists, coming from both industry and academia. These instructors offer a wealth of information and share their expertise as well as life experiences with students. Informal discussions about career trajectories and access to industry are important added benefits to attending these off-campus workshops. Continue reading “Pack a Little Science into Your Summer with Advanced Courses from BTCI”