What Can We Do to Make Your Work Easier? Addressing the Challenges of Working with Primary Antibodies

Posted on by Michele Arduengo, PhD

Scientific progress is iterative. Small advances and bits and pieces of knowledge are accumulated over time with each advance depending on the body of work that has preceded it. Being able to replicate the work from one step to another in this march of science is critical, and it is not easy. We all recognize that a well-documented procedure goes a long way toward enabling reproducibility, but the procedure is not the only hurdle to reproducibility, and it’s not even the main one.

Artistic Image of Hibit Tag

Many of the reagents researchers use are derived from or produced by living organisms. A decade ago, in 2015, an analysis of preclinical research estimated that irreproducibility costs the U.S. around $28 billion a year. When the authors traced the causes, the largest single category wasn’t study design or data analysis. It was biological reagents and reference materials (1).

When Bill Linton first developed the idea of a company that supports scientists in the 1970s, his question was: “What can we do to make your work easier?” The answer he kept getting was the same: researchers wished they could buy reliable restriction enzymes instead of purifying their own for every experiment. It would reduce variability and enable them to focus on the interesting biological questions rather than the requisite protein isolations needed to ask those questions.

Biotechnology and life science research have come a long way since then. We now take reliable, commercially available restriction enzymes for granted. Still, Promega keeps asking Bill’s original question: What can we do to make your work easier? The answers to that question have led to ground-breaking luciferase reporter technology, add-mix-measure assays for everything from cell viability to P450 activity to NADP/H detection, and standardized thaw-and-use primary cell lines for bioassays.

Today’s Difficult Reagent: Primary Antibodies

Among the most difficult reagents to work with and standardize are antibodies. If you are generating polyclonal primary antibodies that are not commercially available to study your target protein, you first need to find an animal with clean pre-immune serum. Usually that serum is evaluated by Western blot, which itself is an inherently fussy technique. And polyclonal antibodies are just that—polyclonal. What is generated after exposure to your antigen is a mixture of antibodies, and the composition of the mixture can change over time as the animal’s immune response matures. This gives you batch-to-batch variability and can make reproducibility more difficult. Commercially produced polyclonal antibodies are subject to the same exact issues. In August 2026, a news article in Nature reported that a metascientist had released a database of more than 18,000 questionable validation images across the catalogs of 15 antibody suppliers. All reflect the antibodies may not be performing like the scientists expect (Garisto 2026). Additionally, production of antibodies requires animal resources. High-quality, application validated antibodies are expensive as well. Using primary antibodies to study proteins is a significant pain point for the bench scientist.

It’s Not Just the Antibodies. It’s the Western Blots Too.

Tagged proteins or high-abundance exogenous expression of a target protein will not always reflect the endogenous protein behavior, localization or function. Large tags can interfere with folding and function; over expression of a protein can produce false protein interactions. Your results could be showing you artifacts resulting from a situation in your cells that is simply not biologically relevant.

If you are studying your target proteins (and other molecules) using Western blotting, post-translational modifications such as phosphorylation, ubiquitination, and cleavage shifts can complicate the interpretation of your results. Multiple bands on a blot can be hard to understand—is the protein cleaved? Is there cross-reactivity with your antibody to another protein? Is your sample degraded?

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Timing Matters in Legionella Testing

Posted on by Parker Smith

Several recent Legionella outbreaks have occurred around the globe. In New York, seven people died and 92 tested positive for Legionnaires disease (prompting improved testing procedures approved by the Governor). In Basel, Switzerland, one person died and twenty-eight contracted Legionnaire’s disease. Even in Linz, Austria, a recent outbreak has led to 20 infected.

What are the key differences between the New York and Switzerland outbreaks: the response time. In New York, operators had to rely solely on slower culture-based methods to identify the outbreak source. In Basel, while operators were able to use qPCR to quickly identify the likely outbreak source, while they also performed culture-based tests to confirm the qPCR results. This enabled operators to identify the contaminated cooling tower and shut it down preventively while awaiting formal regulatory confirmation. The faster source identification with qPCR was a key factor in response speed.

So, what can companies and governments do? They should test more frequently for Legionella pneumophila using faster methods like quantitative polymerase chain reaction (qPCR) and viability qPCR for cleaning verification as part of their operational procedure. Regular testing makes infrastructure safer for everyone and proactively reduces risk for companies.

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Internships at Promega: What Did You Learn?

Posted on by Promega

Each summer, nearly every department at Promega welcomes interns onto their teams. In only three months, these interns make critical contributions to the business and leave with valuable experiences to complement their education.

Four interns shared thoughts on their time at Promega, and how their accomplishments connect to their educational journeys.

Brady Anderson, Scientific Applications Intern, shares his work applying PCR tools to agricultural testing.

Eva Eckel, Environmental Health & Safety (EH&S) Intern, connects three different rotations to her coursework in environmental science.

Ethan Hazra, Process Engineer Co-Op, recalls the rewarding challenge of repairing equipment in an environmental control room.

Ashley Leighton, Corporate Hospitality Intern, describes how she helped her team improve their metrics analysis.

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A New Human Neuron Model for Tau-Targeted Drug Screening

Posted on by Johanna Lee

Every neuron relies on a protein called tau to keep its internal skeleton, the microtubule network, working properly. In a group of brain diseases known as “tauopathies,” tau stops doing its job. It misfolds, clumps together, and eventually contributes to the neuron loss that causes memory changes and shifts in behavior. Scientists studying these diseases have long wanted to watch this process unfold from its earliest moments in living human neurons. However, this has been surprisingly difficult.

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From Chromosomes to the Brain: How HaloTag Is Expanding What We Can See

Posted on by Michele Arduengo, PhD
Artist's 3D concept of HaloTag with linker attaching to a target protein

Sometimes in the life sciences, it’s really tempting to look at a process like mitosis and think, “Wow, we really understand that,” and stop asking questions. In other cases, significant barriers like reliable expression of a non-endogenous reporter in an organ such as the brain is a challenge that seems impossible to overcome. However, those are precisely the moments when science and scientists need to push the boundaries of what we can see. In this post, I discuss two studies where researchers are literally seeing what could not be seen before by developing new methods for looking at their model systems.

In both papers discussed here, the HaloTag® protein and ligands were key to developing new methods allowing scientists to visualize biological phenomena that had been previously inaccessible. HaloTag® protein allows different functionalities to be linked onto a single genetic construct, rapidly and covalently under physiological conditions for experiments ranging from live-cell imaging to capture of protein interaction complexes (1). In the first study, HaloTag-CENP-A + JF635 ligand was the specific tool that let them directly see, in real time, that chromosome-attached microtubules pivot as the spindle elongates. In the second study, HaloTag was used to create a protocol for PET imaging of reporter gene systems in the brain.

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Midges on the Move: Tracking The Oropouche Virus Into New Territory

Posted on by Anna Bennett

For decades, Oropouche virus (OROV) was considered a problem limited to the Amazon Rainforest. OROV is transmitted to humans and animals through the bite of tiny blood-feeding insects called Culicoides midges. The virus causes Oropouche fever, which leads to debilitating symptoms like a high fever and severe headache1. While the virus was first isolated in Trinidad in 1955, it has since been associated primarily with outbreaks in the Amazon Basin. However, in the last two years, over 29,000 confirmed cases have been reported across the Americas, suggesting the virus has expanded well beyond its historical range.

One of the most concerning expansions is the state of Minas Gerais in southeastern Brazil. Unlike the Amazon, Minas Gerais sits within the Atlantic Forest biome, a heavily fragmented landscape shaped by agriculture, urbanization, and a climate distinct from the humid tropics where OROV has traditionally circulated. With more than 1,600 cases of Oropouche fever since January 2024, a consortium of researchers from universities in Brazil and the US have combined their efforts to try to understand the urgent question: what is driving OROV transmission in this unfamiliar territory2?

Image of flies swarming in the sky.
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From a Dying Reef in French Polynesia to a Global Restoration Mission: Meet the Coral Gardeners

Posted on by Alena Nickolenko

Titouan Bernicot founded Coral Gardeners, a nonprofit driving coral reef restoration, at just 18 years old. He was born on a pearl farm on a small atoll, a ring-shaped coral island, in French Polynesia. Instead of playing in the dirt with neighborhood friends after school, Bernicot, the only kid on the little atoll, spent his childhood in the water, immersed in the colorful and flourishing life around him (1). With no shops or markets, the community sustained themselves only with what the island had to offer, therefore relying on a thriving local ecosystem. “A really connected-to-nature way of living” says Bernicot (2). Largely disconnected from the rest of the human world but uniquely integrated with the natural one.

Photo Credit: Coral Gardeners

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Under Pressure: The Nuclear Choreography upon Replicative Stress

Posted on by Promega

Today’s blog is guest-written by Jana Krietsch (University of Zurich), edited by Nour Mozaffari (Promega)

Each time a cell divides, it must make an accurate copy of its entire genome—in human cells, this means roughly 6.2 billion individual DNA building blocks to duplicate. This enormous molecular task takes place inside the nucleus, a crowded, highly organized, yet remarkably dynamic environment. As the DNA-copying machinery moves along the genome, it may encounter roadblocks such as damaged DNA, sequences that are difficult to copy, tightly packed chromatin, or other molecular processes using the same DNA at the same time. These obstacles can slow or stall replication, a phenomenon known as DNA replication stress.

A Hidden Vulnerability of Cancer Cells

Cells are well equipped to deal with replication stress. Depending on the type and severity of the problem, they activate specialized signaling and repair mechanisms that protect replicating DNA. Failure of these responses can jeopardize genome integrity and result in permanent genetic changes that contribute to disease development.

In cancer, oncogenic changes and rapid proliferation places tumor cells under persistent replication stress. This promotes genome instability, a cancer hallmark, and drives tumor evolution. At the same time, it makes cancer cells hyper-dependent on replication stress response mechanisms to survive, creating a hidden vulnerability. Several treatments exploit this Achilles’ heel by increasing replication stress levels beyond what cancer cells can tolerate.

From Sequential Model to Dynamic Choreography

Many stress response pathways have been successfully reconstituted in the test tube. They are typically described as linear sequence of events triggered when an active replication site, termed replication fork, encounters a roadblock: the fork encounters an obstacle, its structure changes, signaling proteins are activated, repair factors are recruited, and DNA synthesis eventually resumes.

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ADC Development: The Questions Running in the Background

Posted on by Elise Johnson

You’ve had food stuck in your teeth at some point during a conversation you thought was going well. Or toilet paper trailing from the back of your shoe on a day you felt particularly put together. Maybe you’ve even forgotten to color in your very blonde eyebrows and spent the rest of the day looking like someone erased the top half of your face. But you had no idea. You’re walking around with the quiet, complete confidence of someone operating on incomplete information.

You weren’t wrong about anything you could see. You just couldn’t see everything, which is a different problem than getting a bad result. A bad result tells you something is wrong, but this doesn’t. This happens in the lab too. The number is clean, the program is advancing, and somewhere in the data, something is happening that your readout has no way to show you.

Antibody-drug conjugate (ADC) development has a version of this problem. The cytotoxicity readout is real, reliable, and correct. It’s also an aggregate, and an aggregate compresses everything that happened into a single number. That number can’t tell you which mechanisms produced it, which ones are underperforming, or what to change if the program stops working. It just tells you cells died, or they didn’t. You’re walking around with the quiet, complete confidence of someone operating on incomplete information.

Cytotoxicity: Where Every Program Begins

Cell viability assays were built to answer one question: did the cells die? Increase the dose, more cells die. Decrease it, fewer do. The curve is clean, the data is reliable, and the payload is doing what it was designed to do. For cytotoxicity, it’s the right question to ask.

That question has an established platform with consistent, reproducible data: our CellTiter-Glo® and RealTime-Glo™ Assays.

For most ADC programs, this is where the measurement work starts and stops, but it should only be where it starts. The question they answer well is only one of several your ADC is raising. The number means what it says, but the question it answers has a boundary, and the boundary leaves you with an incomplete picture.

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Why Antibiotic Resistance Is an Environmental Problem Too

Posted on by Shannon Sindermann
Antibiotics and Bacteria

Antibiotic resistance has an obvious suspect: antibiotics. The more we use them across human and animal medicine, the more we select for the bacteria that survive them (1). But that pressure doesn’t only come from the drugs we designed to kill bacteria. A growing line of research points to the fields, soils and waterways where our food is grown, and to chemicals that were never meant to be antibiotics at all (2,3). It is a reminder of what researchers mean by One Health: human, animal and environmental health are one connected system, not three separate problems, and resistance travels the connections between them (1,3).

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