Reliable DNA Purification from 3D Cell Cultures

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.

A spheroid of ~1,000 human liver cells. Image provided by Insphero.
Continue reading “Reliable DNA Purification from 3D Cell Cultures”

WiSciFest 2019: A Retrospective

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.

Thank you to the tablecloth for providing the darkness needed to grab this pic.
Continue reading “WiSciFest 2019: A Retrospective”

Anti-Cancer Drugs Are Pro-Coral

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.

Corals living on shallow patch reefs in Palau. The Palau International Coral Reef Center is the staging ground for the research on mechanisms allowing corals to thrive in warming waters.

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.

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Brazilian University Swatting at Leishmaniasis Parasite

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.

Microscopic image of Leishmania parasite
Microscopic image of Leishmania tropica. Credit: Brian E. Keas at Michigan State University.

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.

Lighting Up GPCR Research with Bioluminescent Tagging

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”

Eight Considerations for Getting the Best Data from Your Luminescent Assays

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!

Bad data
These data are garbage!

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”

Help the Environment through…Gaming?

Did you know that April is Earth Month? While you should be good to the planet every day, this month you should be extra good. Maybe buy it a nice pair of socks or something. Compliment it on its majestic mountains. Or, you could compete to see who can be the best at being nice to the planet, like we’re doing here at Promega with our Green Go Challenge.

Green Go Challenge bingo sheet
Get it? It’s like bingo, but green.

Continue reading “Help the Environment through…Gaming?”

Science Visitors Only: Watching Life Grow on a New Island

We spend a lot of time looking at history and imagining—”what was it like when…?” As a biologist, I find myself most drawn to stories about the evolution of life. Why does this plant have purplish leaves? How did this species end up in a symbiotic relationship with this other species? How did this animal get to this tiny island 20 miles off the Southern coast of Iceland?

The volcanic island of Surtsey erupting in 1963.
The newly formed island of Surtsey erupting in 1963.

That last one was too specific to be rhetorical, wasn’t it? The volcanic island of Surtsey broke the ocean surface on November 14, 1963, and continued to erupt until June 5, 1967, reaching its maximum size of 2.7 km2 (about the size of Central Park in New York City). At this size, it was large enough to be a good site for biocolonization. Only a few scientists are allowed to visit the island, ensuring that colonization of the island can occur without human interference. Continue reading “Science Visitors Only: Watching Life Grow on a New Island”

Extra extra: Read All About Tautonyms

If you’re active on #sciencetwitter, you may have seen a thread recently about tautonyms. “Tautonym” is a cool word for scientific names where the genus and species are the same word, For example, Vulpes vulpes is the scientific name for the red fox.

I have taken great delight in sharing these tautonyms with friends, colleagues, and random strangers on the bus. However, the problem that I keep having is that people want more details about something than the name. If you’ve had that problem, too, then this blog is for you. Continue reading “Extra extra: Read All About Tautonyms”

“We’re From NASA”: How Citizen Science Helped Find Ultima Thule

The science world is a-twitter with excitement lately, following the recent arrival of the New Horizons spacecraft at 2014 MU69, dubbed “Ultima Thule” by popular vote. The name means “beyond the borders of the known world”, signifying Ultima Thule’s status as the most distant object ever visited by Earthly spacecraft. Ultima Thule is a dark reddish rock in the Kuiper belt, a contact binary formed by two smaller rocks coming together in what was presumably a gentle fashion.

Do you wanna build a snowman? Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Reaching this space snowman 6.5 billion kilometers away from Earth took brains, dedication, ingenuity and the help of an unnamed Argentinian man and his daughter.

To successfully intercept Ultima Thule, the New Horizons mission team needed to answer some questions, such as “What trajectory is Ultima Thule on?” and “Is there any space debris around Ultima Thule that will destroy our spacecraft?” Being so small (~30km diameter at its widest point), observing Ultima Thule directly from this far away would be too difficult, so the team relied on data gathered during stellar occultations, i.e., when Ultima Thule passed in front of a star.

One of these occultations occurred on July 17, 2017, in the Patagonia region of Argentina. The team had already struck out twice in trying to observe Ultima Thule passing over a star: once in South Africa, and again using the airborne telescope SOFIA over the Pacific Ocean, so tension was already running high.

On this particular night, it happened to be very windy where the observation team was, which is bad news when you’re trying to hold steady focus on a tiny object that’s really far away. The team found themselves needing help to shield the telescopes they had brought with them from wind vibrations, and get the data from the star “without it jiggling around all over the place”, as planetary scientist Anne Verbiscer puts it.

Where does one find volunteers for an astronomical observation? Well, apparently even in Argentina NASA is known and loved, and help can be found just by walking into the community. “If you just started out with ‘We’re from NASA,’ people started coming out of the woodwork,” said Dr. Verbiscer. And that is how one Argentinian man and his daughter ended up spending their evening blocking the wind from a telescope using a truck, a tarp and some plywood, allowing the NASA folks to collect the data they needed to send New Horizons to Ultima Thule.

Want to learn more about the search for Ultima Thule? Check out the episode of NOVA that inspired this blog!