Traditionally, scientists have relied on flat, two-dimensional cell cultures grown on substrates such as tissue culture polystyrene (TCPS) to study cellular physiology. These models are simple and cost-effective to culture and process. Within the last decade, however, three-dimensional (3D) cell cultures have become increasingly popular because they are more physiologically relevant and better represent in vivo conditions.
This past weekend was the 9th Annual Wisconsin Science Festival, and we at Promega were excited to join in the celebration of science throughout the state. We participated in the Discovery Expo on Thursday and Friday, where dozens of demonstrations and exhibits were scattered throughout the Wisconsin Institute for Discovery building. Thousands of children on field trips filled the halls, eager to poke and prod at strange and exciting new things.
At our table, we talked about the science of bioluminescence. With 3D-printed firefly luciferase models in hand, we showed the glow of recombinant luciferase to the incoming children and explained to them how scientists could use bioluminescence like a tiny “flashlight” to look inside of cells and watch what’s happening. Our learners received a nice little reward for their attentiveness in the form of glow-in-the-dark firefly stickers.
With average sea surface temperatures increasing around the world, coral bleaching events are growing in extent and severity. More than two thirds of the corals in the Great Barrier Reef, the world’s largest coral reef, have already bleached. While the physiological consequences of coral bleaching are well-studied, we still don’t fully understand how bleaching happens on a cellular level.
Steve Palumbi at Stanford University is delving deeper into the mechanisms by which coral bleaching occurs. In 2018, Promega pledged $3 million over three years to the nonprofit Revive & Restore Catalyst Science Fund, to identify and develop advanced techniques for conservation, enhancing biodiversity, and genetic rescue. Palumbi was awarded the first grant from this fund to study the genomic stress trigger that causes corals to bleach in warming oceans.
Continue reading “Anti-Cancer Drugs Are Pro-Coral”The Medicinal Chemistry Center (CQMED), headquartered at Campinas State University in Brazil, recently started a project in partnership with Promega to develop drugs that can be used against Leishmania. This genus of protozoans is the etiological agent of leishmaniasis, transmitted to humans by sandflies.
Leishmaniasis is classified as a neglected tropical disease that mainly affects poor communities. Symptoms include large skin sores and an enlarged spleen. The challenge in developing drugs to treat Leishmania is finding appropriate therapeutic targets. These targets are normally proteins whose inhibition leads to death of the parasite. In addition to pharmaceutical company Eurofarma, whose goal is to develop drugs for Leishmania, Promega was chosen to help solve this problem because of our NanoBRET™ Target Engagement (TE) assay*, a well-established technique for measuring protein interactions. In this assay, NanoLuc® luciferase is attached to the protein of interest, and a fluorescent NanoBRET™ tracer molecule is added to the cells. This produces a BRET signal. When a competing ligand is added, it will displace the tracer molecule, enabling quantification of the strength of the interaction compared to the tracer molecule..
A challenge that researchers will face will be ensuring that the NanoBRET™ tracer reaches the inside of the parasite cells; because Leishmania is an intracellular parasite, molecules need to cross the host cell membrane, the membrane of the vacuole containing the parasites, and the membrane of the parasite itself. Another challenge the slow reproduction of Leishmania within macrophages. On top of that is the fact that the parasite’s metabolism varies depending on its biological cycle, meaning that there could be long periods of time during which a drug’s therapeutic target is not expressed in the cell, during which time the drug would have no effect. The ideal target would be expressed at high levels throughout the cell cycle.
The project is being led by Rafael Couñago, a researcher at CQMED, and Promega scientists Matt Robers and Jean-Luc Vaillaud.
*An earlier version of this blog incorrectly said that these experiments are based on the NanoBRET™ assay using HaloTag® protein.
G Protein-Coupled Receptors (GPCRs) are a very large, diverse family of transmembrane receptors in eukaryotes. These receptors detect molecules outside the cell and activate internal signaling pathways by coupling with G proteins. Once a GPCR is activated, β-arrestins translocate to the cell membrane and bind to the occupied receptor, uncoupling it from G proteins and promoting its internalization.
Reporter tags are useful for studying the dynamics of GPCRs and associated proteins, but large tags can disrupt the receptors’ native functioning, and often overexpression of the tagged protein is required to obtain sufficient signal. Here is one example of how researchers have used the small, bright NanoLuc® luciferase to overcome these common challenges and answer questions about GPCRs.
Continue reading “Lighting Up GPCR Research with Bioluminescent Tagging”The stage is set. You’ve spent days setting up this experiment. Your bench is spotless. All the materials you need to finally collect data are laid neatly before you. You fetch your cells from the incubator, add your detection reagents, and carefully slide the assay plate into the luminometer. It whirs and buzzes, and data begin to appear on the computer screen. But wait!
Don’t let this dramatic person be you. Here are 8 tips from us on things to watch out for before you start your next luminescent assay. Make sure you’ll be getting good data before wasting precious sample!
Continue reading “Eight Considerations for Getting the Best Data from Your Luminescent Assays”
We have published 130 blogs here at Promega this year (not including this one). I diligently reviewed every single one and compiled a list of the best 8.5%, then asked my coworkers to vote on the top 5 out of that subset. Here are their picks:
No surprises here, everyone loves water bears. Kelly Grooms knows what the people want.
This past weekend, I had the opportunity to be a part of “Once Upon a Christmas Cheery in the Lab of Shakhashiri”. Bassam Z. Shakhashiri is a professor of chemistry at the University of Wisconsin–Madison who is well-known for his fun science demonstrations and a fervent dedication to public science communication. Once Upon a Christmas Cheery started in 1970 as an end-of-semester treat for Dr. Shakhashiri’s freshman chemistry class; by 1973, the Christmas lecture had become so popular that Wisconsin Public Television offered to broadcast it during Christmas week, and this collaboration has continued uninterrupted ever since.
That’s 49 years of Christmas lectures, commemorated by making indium, the 49th element, the Sesame Street-esque “sponsor” of the show. It helps that indium burns bright violet, the name of Dr. Shakhashiri’s granddaughter and hence his favorite color. The color purple made a firm foundation for many aspects of the show: The chrysanthemums frozen in liquid nitrogen were purple, as was the balloon I inflated during my spiel on air movement. Most of the set was various shades of purple, too.
In my second or third year as a graduate student, I had to ship some microfluidic masters to a collaborator in Kenya. The masters were extremely fragile and took me several days in a cleanroom gown to make. I was horrified at having to send them on a perilous journey overseas, and somewhat flabbergasted that they made it to Nairobi whole and well. And yet, every day thousands of delicate items zoom around the world and arrive at their destinations in one piece. How?
A couple months ago, I visited the lab where our packaging engineers (yes, that’s a thing) do their work. Here’s what I learned. Continue reading “An Ode to Packaging Engineers”
Dennis Dimick has focused his journalism career on the collision between human aspiration and the planet. The son of fisheries biologists, Dimick grew up on a farm in Oregon’s Willamette Valley, and he holds degrees in agriculture and agricultural journalism from Oregon State University and the University of Wisconsin-Madison. In his 35 years at National Geographic, he served for over a decade as the magazine’s environment editor, and guided major projects on climate change, energy, freshwater, population, and food security. Dimick is co-founder of Eyes on Earth, a project meant to inspire a new generation of environmental photographers.
As a young man, Dimick witnessed firsthand the price of progress when his family’s farm was cut in half by the construction of an interstate beltway. This invasion of their farm, in addition to the clear-cut logging of nearby forests where Dimick had spent his youth, combined to sensitize him to the profound impacts of human progress on the Earth. Early photography experience and his personal connection to the effects of human progress led to a life and career spent combining these two dimensions.
In anticipation of his participation in the 2018 Wisconsin Science Festival, I asked Mr. Dimick some questions about photojournalism, and what it’s like documenting the human impact on the environment. Some of his answers have been slightly edited for clarity.
What does it take to be a good environmental photographer?
Continue reading “Living in the Anthropocene: A Photojournalist’s Perspective”