In May 2017, a surprising discovery was made in the woods of Bayfield County, Wisconsin, just about a 5-hour drive north of Promega headquarters. Jonathan Martin, Associate Professor of Forestry at Northland College, was exploring the forest with an ultraviolet (UV) light in search of fluorescent lichen or plant life. What he found instead was a bright pink glow coming from a most unexpected source—a flying squirrel.
Continue reading “The Secret Fluorescent Life of Flying Squirrels”
Think about the last time you gave a presentation. The feeling of having “butterflies in your stomach”. Or when you meet someone for the first time, that “gut feeling” of whether you two will get along. In our day-to-day lives, we often associate what happens in the gut with what goes on in our brain. In fact, scientific evidence suggests that our gut and our brain frequently communicate—through gut microbes. Apparently, the existence of trillions of bacteria and eukaryotes in our gut is not only crucial for our physical health, they may also be important for our mental health.
The 2019 iGEM Competition is on the horizon and team registration opens this month. We’re excited to partner with the iGEM Foundation again this year and offer our support to the young scientists who participate. If you’re starting an iGEM project, there are going to be things you need along the way. We are pleased to share a number of different ways we can help your iGEM team from now until the Giant Jamboree.
Grant Sponsorship
Tell us about your iGEM project and your team could win a 2019 Promega iGEM Grant Sponsorship. Ten winning teams will each receive $2000 in free Promega products to use for their iGEM projects. Tell us about your project—What problem are you addressing? What is your proposed solution? What challenges does your team face? Last year’s winning teams selected from a wide range of reagents and supplies, including master mix, restriction enzymes, ligase, DNA purification kits, expression systems, DNA ladders and markers, buffers and agarose. Click here to apply! Continue reading “It’s Almost iGEM Season—Help Is On The Way!”
This is a guest post from Katarzyna Dubiel, marketing intern in Cellular Analysis and Proteomics.
“The objective of my experiment was to test the NanoBRET™ assay as if I was a customer, independent of the research and development team which develops the assay.”
Designing and implementing a new assay can be a challenging process with many unexpected troubleshooting steps. We wanted to know what major snags a scientist new to the NanoBRET™ Assay would encounter. To determine this, we reached out to Laurence Delauriere, a senior applications scientist at Promega-France, who had never previously performed a NanoBRET™ assay. Laurence went step-by-step through the experimental process looking at the CRAF-BRAF interaction in multiple cell lines. In an interview, Laurence provided us with some tips and insights from her work implementing the new NanoBRET™ assay.
In a few words, can you explain NanoBRET?
“NanoBRET is used to monitor protein: protein interactions in live cells. It is a bioluminescence resonance energy transfer (BRET) based assay that uses NanoLuc® luciferase as the BRET energy donor and HaloTag® protein labeled with the HaloTag® NanoBRET™ 618 fluorescent ligand as the energy acceptor to measure the interaction of two binding partners.” Continue reading “Executing a NanoBRET™ Experiment: From Start to Data”
Large-scale analyses of the proteome have revealed proteomic changes in response to disease, and these changes hold great promise for diagnostics and treatment of complex disease if proteomic analysis can be brought into the clinical laboratory. Successful and reliable large-scale proteomics requires sample preparation workflows that are reproducible, reliable and show little variability. To bring proteomics into the clinical laboratory, standardized procedures and workflows for sample prep and analysis are required to generate valid, actionable results on a time scale useful for the clinic.
The two most common sample types analyzed for clinical proteomics are body fluids and tissue biopsies. To process these kinds of samples, there are two initial steps: tissue solubilization, followed by proteolytic digestion. Solubilization of solid tissues is the most labor-intensive and produces the most variable results.
The introduction of pressure cycling technology (PCT) using Barocycler instrumentation has greatly improved both tissue solubilization and digestion consistency. The PCT-based sample preparation protocols generally utilize urea as a lysis buffer for protein denaturing and solubilization. Urea has several drawbacks including inhibiting trypsin activity and introducing unwanted modifications like carbamylation.
Lucas and colleagues analyzed whether replacing urea with SDC would produce similar tissue digestion profiles and improve the PCT method.
SDC allowed the use of higher temperatures compared to urea, and hence the first step (lysis, reduction, and alkylation) was performed at 56 °C. The second digestion step in the Barocycler was optimized, and the third step was eliminated. To further reduce digestion time, they capitalized on Rapid Trypsin/Lys-C. Rapid Trypsin/Lys-C maintains robust activity at 70 °C, and allowed Barocycler digestion to be performed in a single step, completing digestion in 30 cycles (approximately 30 min) rather than 105 minutes, streamlining the protocol.
The data presented an improved conventional tissue PCT approach in a Barocycler by replacing urea and proteolytic enzymes with SDC, N-propanol, and modified commercially available enzymes that have higher optimum temperatures.
Lucas, N. et al. (2019) Accelerated Barocycler Lysis and Extraction Sample Preparation for Clinical Proteomics by Mass Spectrometry. J of Proteome Res 18, 399–405.
In recent years, scientists have been able to refine their molecular tools to resurrect ancient DNA from human graves and determine that yes, Yersinia pestis was the causative agent for the Black Death in the 14th century and the Plague of Justinian in the 6th century. As more and more human graves have been uncovered, their DNA has revealed many secrets that scientists even ten years ago were unable to discover. With the ability to sequence entire genomes of bacteria that died with their hosts hundreds and even thousands of years ago, researchers are exploring the rise and possible spread of Y. pestis. Each new member sequence adds to the Y. pestis family tree, pinpointing the origin of this bacteria as it diverged from its ancestor Y. pseudotuberculosis. Peering into the past, scientists have been able to track down a strain of Y. pestis from individuals in a Swedish passage grave that is basal to known strains and that the authors of a Cell article suggest has interesting implications.
This pathogenic journey into history started by analyzing ancient DNA data sets from the teeth of individuals present in a communal passage grave in Gökhem parish, located in western Sweden, for any disease-causing microbial sequences that might be present. Y. pestis was flagged in one 20-year-old female dated 4,867–5,040 years ago. The bacterial sequences from this individual, named Gok2, were more closely aligned with Y. pestis than the Y. pseudotuberculosis reference genome. Continue reading “Expanding the Plague Family Tree: Yersinia pestis in the Neolithic”
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”
When Wisconsin plunged into a deep freeze during last week’s polar vortex, I built a roaring fire in my fireplace and settled into my armchair with a thick blanket and a video game controller. Except for the twenty minutes I spent driving to and from the office, I stayed warm and toasty.
Birds, however, don’t have it quite as easy. To survive freezing temperatures, non-migratory birds have developed many interesting adaptations. Many species grow extra down layers and huddle together for wind protection. Others, like the black-capped chickadee, use a process called regulated hypothermia to drop their resting body temperature by as much as 22°F to conserve energy. I’m particularly fascinated by the process of regional hypothermia—many species of ducks and gulls use a countercurrent heat exchange system to keep vital organs warm while letting temperatures fall in extremities.
Birds that aren’t accustomed to cold weather don’t have these adaptations, though. When a bird—or any animal—ends up far outside of its natural habitat, the consequences can be deadly.
Continue reading “Goodbye to the Most Famous Bird in Maine”Today’s guest blog is written by Aparna Shah, a Post-Doc at Johns Hopkins University. Aparna visited the Promega campus in Madison, Wisconsin on January 18, 2019 and offered to share her experiences.
I don’t recall ever having won a contest before, let alone the grand prize! In fact, I did a double take when I first read the email informing me that my SciArt submission had been selected as a winning entry for the Promega Art Contest for Creative Scientists. What did I win, you ask? A free trip to Madison, WI to meet with the team behind the contest and explore Promega’s headquarters!
I first heard about the contest on the HelloPhD podcast and considered participating primarily to support the SciArt movement. A couple of days later, I came across a perfectly-timed tweet about the contest that nudged me out of procrastination mode and reminded me to follow through with it. I’m going to take a second here to pitch both HelloPhD and Twitter to you. Regardless of whether you’re an undergraduate student interning in a science lab or a senior postdoc, the HelloPhD podcast is incredible at calming you down while you’re on the roller coaster ride called academia. As for Twitter, I can think of several pros for using it. But in the context of this post, it is one of the best resources for discovering opportunities that match your interests.
Continue reading “Oh, the Places You’ll Go, Thanks to Science!”
A recent PNAS article tracked the careers of scientists in three different fields based on research paper authorship. They found that, over a 50-year span, there was a dramatic reduction in how long scientists remained in each field, which they termed “survivability.” More than half of the scientists that started out in the 1960s published in their field for an average of 35 years, while about half of scientists starting in the 2010s published in their field for an average of 5 years1. Tracked academic researchers were classified into three categories: transients (authors who had only one publication during their career), dropouts (authors who stopped publishing at various career levels), and full-career scientists (authors who continue to publish in the field). Overall, the data showed that there are an increasing number of transients that contribute to scientific papers. Thus, the authors of the PNAS article concluded that the demographics in those academic fields are shifting toward scientists who leave the field quickly. The observed increase in the number of scientists who are temporarily in academia makes sense, given the number of PhDs relative to the limited number of faculty positions and permanent staff scientist roles. However, the terms “survivability,” “transients,” and “dropouts” give the impression that leaving academia means that these scientists have ended their career or failed.
Continue reading “A Conscious Decision to Change Careers Should Not Be Mistaken for Failure”