Ah, the wonders and frustrations of cloning. We’ve all been there. After careful planning, you have created the cloned plasmid containing your DNA sequence of interest, transformed it into bacterial cells and carefully spread those cells on a plate to grow. Now you stand at your bench gazing down at your master piece: a plate full of tiny bacterial colonies. Somewhere inside those cells is your DNA sequence, happily replicating with its plasmid host. But wait – logic tells you that not ALL of those colonies can contain your plasmid. There must be hundreds of colonies. Which ones have your plasmid? You begin to panic. Visions of yourself old and grey and still screening colonies flash through your mind. At the next bench, your lab-mate is cheerfully selecting colonies to screen. Although there are hundreds of colonies on her plate as well, some are white and some are blue. She is only picking the white colonies. What does she know that you don’t? Continue reading “Selecting the Right Colony: The Answer is There in Blue and White”
Sustainability is a bit of buzzword lately—for good reason—but knowing how to be more sustainable and actually putting sustainable practices in action are not the same thing. This may be one reason why scientists have been slow to adopt change in their laboratories. By sponsoring My Green Lab, we’re hoping to help spread the message that there are simple changes researchers can make in their labs to significantly impact sustainability.
Here are some easy ways to reduce energy, water and waste in your lab and start making your research more sustainable.
Compared to office buildings on campus, academic lab buildings consume 5 times more energy. To put that into perspective, labs typically consume 50% of the energy on a university campus despite occupying less than 30% of the space. Fortunately, reducing energy usage can be one of the easiest ways to make your lab more sustainable. Continue reading “Lab Sustainability: Easy as 1-2-3”
The cause of type 1 diabetes (T1D) is not well understood. What is known is that in T1D, immune cells attack pancreatic islet cells that produce insulin. In addition, insulin is an autoantigen that activates T cells in diabetic persons.
A new discovery by Ahmed et al. could further T1D understanding. These findings are also setting B and T cell paradigms on their ear.
About B Cells and T Cells
B cells (B lymphocytes) are part of the cellular immune response. They act by means of surface receptor molecules that are immunoglobulins. These B cell receptors are created by highly variable gene rearrangements that result in a huge variety of these surface immunoglobulin molecules. The beauty of B cell receptors (BCR) lies in the fact that, through random gene rearrangements comes a such large variety of B cell surface receptors, that any foreign antigen that makes its way into the body is recognized and snagged by a B cell receptor.
B cells then internalize, process and present these antigens to T cells. Continue reading “B Cells, T Cells and Now X Cells?”
Celebrate National Fresh Fruits and Vegetables Month by adding more color to your plate. Not only are fruits and vegetables tasty, but they provide a variety of nutrients, vitamins, minerals and fiber to help you feel energized. Fruits and veggies also help reduce the risk of many diseases including heart disease, high blood pressure and certain cancers. Widely recognized healthy eating tips urge individuals to consume mostly plant based foods, eat 4-5 cups of fruits and veggies every day, and avoid processed foods.
Ways to Get Fresh Fruits and Vegetables: Farmer’s Markets are Radish
A great way to purchase fresh fruits and veggies is by attending a farmer’s market. Farmer’s markets are community centerpieces. Shopping at markets helps support local agriculture and recirculates money back into the community. Many times, shoppers can find food that is pesticide-and herbicide-free. Since food is sourced from nearby, shopping at a market helps save the energy and petroleum that is used to ship food around the world. Plastic waste can also be prevented, just remember to bring your own reusable produce bags. Continue reading “Nothing Beets Locally Grown”
Targeting a single protein and making it disappear from the cell is quite the magic trick, and there are various molecular tools available for this task. You can use RNA interference, which prevents a protein from being made, inhibitors that bind the protein, rendering it unavailable for use or even gene editing tools like CRISPR that can remove it from the genome. But did you know that you can target an existing protein for destruction, using the cell’s own garbage disposal system to degrade the protein? All you need is a molecule that can connect your protein to one with a role in cellular protein degradation and your protein can be destroyed. Continue reading “PROTACs, PHOTACs and LYTACs: How to Target a Protein for Degradation”
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 use of mass spectrometry for the characterization of individual or complex protein samples continues to be one of the fastest growing fields in the life science market.
Bottom-up proteomics is the traditional approach to address these questions. Optimization of each the individual steps (e.g. sample prep, digestion and instrument performance) is critical to the overall success of the entire experiment.
To address issues that may arise in your experimental design, Promega has developed unique tools and complementary webinars to help you along the way.
Here you can find a summary of individual webinars for the following topics: Continue reading “Bottom-up Proteomics: Need Help?”
Sunscreen usage is increasing, with more people using SPF to prevent the very real threats of skin cancer and early signs of aging. While slathering on the sunscreen is unarguably important to protect your skin from the sun, new concerns arise linking sunscreen chemicals to coral reef bleaching, as an estimated “14,000 tons of sunscreen is believed to be deposited in the oceans annually.”
Coral reefs are the most productive marine ecosystem known. Coral reefs protect coastlines from storm surge and support commercial and recreational fisheries and tourism. Unfortunately, certain chemicals in sunscreen are causing coral reefs to bleach; thus, becoming more susceptible to viral infections. The reefs eventually turn white and die. Coral reef bleaching is the leading cause of coral reef deaths worldwide. This conversation is an important one to discuss leading up to the celebration of World Oceans Day on June 8.
Chemical recreational sunscreen contains oxybenzone, a toxic synthetic molecule. Oxybenzone is prevalent in the majority of mainstream sunscreen brands. This ingredient results in extreme harm to marine organisms. The Ocean Foundation emphasized that, “A single drop of this compound in more than 4 million gallons of water is enough to endanger organisms.” Even if you do not physically go in the water, the chemical can be washed into the ocean through the sand.
In response to this issue, many countries and resorts are banning “reef-toxic” sunscreen. Hawaii and Key West recently passed a bill banning the sale and distribution of any sunscreen that contains 10 toxic ingredients, including oxybenzone. This bill goes into effect January 2021. Many dermatologists are concerned for public safety, highlighting that banning certain sunscreens will decrease overall use. Unprotected sun exposure it the most preventable risk factor for skin cancer. From the perspective of a customer, it is important to be actively informed on what constitutes a “reef-safe” sunscreen. Oxybenzone can pop-up in many moisturizers, primers, and foundations that contain SPF. Reef-friendly options include: any version of chemical sunscreen that does not contain oxybenzone.
With a commitment to protect the environment, Promega has pledged $3 million over the next three years to the Revive and Restore Catalyst Science fund. Organization founders and scientists are focused on an extremely long-term view of wildlife conservation. This fund invests in proof-of-concept research projects that offer innovative solutions for conservation challenges and threatened ecosystems. Marine biologist Steve Palumbi was awarded the first Fund grant to investigate the triggers that may cause corals to bleach. Palumbi reflects on his research in an interview with Stanford News stating, “The report reflects a sense of urgency. We need to start helping corals now, so that as the climate gets worse—and it will inevitably get worse—we’re a little bit in front of the problem. There’s this amazing sense that we all have to just jump in and try ideas and fail so that, eventually, someone comes up with the answers we need.”
It’s FINALLY time to announce the winners of the 2019 Promega iGEM Grant! We received over 150 applications this year, so picking the top 10 was very tough. As always, we’re impressed by the amazing work iGEM teams are doing in the lab and in their communities. The 10 winners listed below will receive $2,000 in free Promega products.
Good luck to all teams competing in iGEM this year, and congratulations to our winners! Don’t forget that Promega has free technical support for all teams competing in iGEM. Our scientists are excited to help out. You can also check out our iGEM Sponsor page, which has tools and resources to help make your project a success. Continue reading “Announcing the 2019 Promega iGEM Grant Winners”
It’s a question I’m asked probably once a week. “What wavelength do I select on my luminometer when performing a luciferase assay?” The question is a good and not altogether unexpected one, especially for those new to bioluminescent assays. The answer is that in most cases, you don’t and in fact shouldn’t select a wavelength (the exception to this rule is if you’re measuring light emitted in two simultaneous luciferase reactions). To understand why requires a bit of an explanation of absorbance, fluorescence, and luminescence assays, and the differences among them.
Absorbance, fluorescence, and luminescence assays are all means to quantify something of interest, be that a genetic reporter, cell viability, cytotoxicity, apoptosis, or other markers. In principle, they are all similar. For example, a genetic reporter assay is an indicator of gene expression. The promoter of a gene of interest can be cloned upstream of a reporter such as β-galactosidase, GFP, or firefly luciferase. The amount of each of these reporters that is transcribed into mRNA and translated into protein by the cell is indicative of the endogenous expression of the gene of interest. Continue reading “Why You Don’t Need to Select a Wavelength for a Luciferase Assay”