Evaluating DNA Quantity and Quality in FFPE Tumor Samples After Prolonged Storage Using the ProNex® DNA QC Assay

When tumors are surgically removed from cancer patients, the tumor samples are often stored as formalin-fixed and paraffin-embedded (FFPE) tissue blocks. In many cases, tumor samples need to be analyzed several years after diagnosis in order to develop target treatments. But what happens to the DNA after years of storage in FFPE blocks? How well is the DNA preserved?

Scientists in France tried to answer this question in a recent study published in Virchows Arch. The authors extracted DNA from 46 FFPE tumor samples of lung, colon and the urothelial tract, all stored between 4–6 years at room temperature. They then compared the quantity and quality of the DNA to DNA that had been extracted before storage. Using common fluorimetry and qPCR methods, the authors found that the total amount of DNA extracted decreased by half. In addition, the percentage of amplifiable DNA decreased from 56% to only 15% after prolonged storage. Continue reading

Your Kid Can Become a Citizen Scientist with These 7 Apps

Has your kid ever asked you what you do in the lab all day? (“Hmm…good question, what am I doing all day?”) A simplified answer might sound something like this: I observe, ask a question, collect data, and use those data to answer the question (or at least try!). The scientific method may be difficult to explain to a kindergartner, but you can always start by encouraging them to observe the world around them, ask lots of questions—and even help collect data. In fact, with the help of technology, your child can become a scientist without 7 long years in graduate school or ever setting foot in a lab. A “citizen scientist”, that is. All you need is a smart phone. Here is a list of apps that can make your kid, grandma, neighbor, anyone, become a citizen scientist by helping professional scientists collect data for their research. The apps are all free to download, easy to use and have a real impact on the scientific community.

1. iNaturalist:

Are you sick of not knowing the answer when your child asks “What’s this bug?” on a nature walk? You need the iNaturalist app. Here’s how it works: You observe an interesting plant/insect/animal, take a photo, and the app identifies the name of the species and some basic information about it. There is also the option to share your finding with other users and they can suggest an identification. iNaturalist shares your findings with scientific data repositories like the Global Biodiversity Information Facility to help scientists understand biodiversity. You can even set up scavenger hunt-like activities: iNaturalist birthday party anyone? Continue reading

Measuring Metabolic Changes in T cells with the Lactate-Glo™ Assay

Immunometabolism

Welcome to the emerging frontier of immunometabolism. A decade ago, immunology and metabolism were seen as two distinct areas of study. However, we now know that specific metabolic activities are required for proper immune cell differentiation and function. In tumor microenvironments, immune cells may even alter their metabolism to compete with tumor cells for limiting nutrients.

Glucose metabolism in Naïve vs Effector T cells

What does your car and T cells have in common? They both shift gears! You can shift gears on your car to change the way the engine’s power is used to match driving conditions; when you’re going uphill, you switch to a higher gear. Similarly, when T cells are activated, they change the way they generate energy to match functional needs. This makes sense because activated T cells (known as effector T cells) require more energy and biomass to support growth, proliferation and effector functions.

While cars run on gas, the main fuel for T cells is glucose. Each glucose molecule is broken down into pyruvate while generating 2 ATP molecules. Naïve T cells completely oxidize pyruvate through oxidative phosphorylation to generate 36 ATPs per glucose molecule. However, when T cells are activated and become effector T cells, glycolysis is used to produce 2 ATPs per glucose molecule. Continue reading

iGEM: Saving the World with Science

The University of Chicago 2016 iGEM team group photo (Photo credit: Julia Byeon)

Every year, groups of teenagers gather together and brainstorm ways to save the world—with science. The International Genetically Engineered Machine (iGEM) Foundation is a non-profit organization that is dedicated to educating young scientists and enhancing open community and collaboration in the field of synthetic biology. They hold a competition every year with hundreds of teams participating from around the world.

Last year, Promega provided cloning reagents to the University of Chicago iGEM team, and they received a bronze medal for their work. We asked two of the team members, Steve Dvorkin and Julia Byeon, about their experience. Steve is a junior and majors in biology; he is co-president of the team this year. Julia recently graduated and works in public policy. Continue reading