Do you count colonies on agar plates? Do you often need to average counts over a series of plates? The Promega Colony Counter app for iPhone® (3GS, 4S, and 5) and iPod® Touch (4th and 5th generation) allows you to take a picture of your plate, obtain a good first-guess count and refine it quickly by marking additional colonies and masking areas where the app may have over-counted.
The app is available for purchase for 3.99 USD from the iTunes store in North America and Europe.
CD73 also known as 5´-Ectonucleotidase (NT5E) is a membrane-anchored protein that acts at the outer surface of the cell to convert AMP to adenosine and free phosphate. CD73 activity is associated with immunosuppression and prometastatic effects, including angiogenesis. CD73 is highly expressed on the surfaces of many types of cancer cells and other immunosuppressive cells (1). A recent study by Quezada and colleagues showed that the high concentration of adenosine produced by the CD73-catalyzed reaction on glioblastoma multiforme cells, which are characterized by extreme chemoresistance, triggered adenosine signaling and in turn, the multi-drug resistance (MDR) phenotype of these cells (2).
Because of the roles of adenosine in immunosuppression, angiogenesis and MDR phenotypes, CD73 (NT5E) is an attractive therapeutic target. However, the current methods of assaying for the ectonucleotidase activity, HPLC and a malachite green assay, are cumbersome and not suited to high-throughput screening. The HPLC assay is expensive and difficult to automate and miniaturize (3). The malachite green assay is sensitive to phosphate found in media, buffers and other solutions used in the compound-screening environment.
To address the problem of developing a reliable high-throughput screening assay for CD73, Sachsenmeier and colleagues (3) looked to a luminescent ATP-detection reagent.
Continue reading “Screening for Inhibitors of CD73 (5´-ectonucleotidase) Using a Metabolite Assay”
When I first learned that I had won a copy of The Where, The Why and The How in the book lottery at ScienceOnline 2013, I couldn’t believe my luck. I never win anything, at least not anything that I actually want. And I wanted a copy of this book.
The book is beautiful to hold. The linen binding is beautiful, reminiscent of bygone days when book binding was a practiced art. The paper is thick and smooth, a tactile pleasure as you turn each page; the pages themselves sound substantial as you flip through the book. Even the smell of the book is delightful—bringing to mind the stacks of old books filling a great library, even though what you hold in your hand is a new work. The science paisley inside covers of the book are a delight to look at, comprising various science icons intricately woven into an astounding tapestry.
I was expectant when I opened the book for the first chance for a serious read. Continue reading “The Where, The Why and The How: A science writer and a graphic designer have a conversation”
How do you imagine walking through a Jurassic forest? If you are lucky enough to find a fossil-rich region like the Junggar Basin in Northwest China, you could turn to the fossil record to get an idea of the sizes and shapes of the animals you might encounter (1). You could look to fossils of plants to reconstruct the canopy—especially since in this region, many stumps were found in growth position, and there are megaplant fossils as well as fossils of seeds and spores. You could look through databases of fossils and findings and create a detailed computer model of the plant and animal life that you might see or touch as you walk. You could look to geological records to understand what temperature and humidity might have felt like. But how do you imagine the sounds, particularly the animal calls and songs? What do you hear in a Jurassic forest?
Continue reading “A Song from the Mid Jurassic”
Notes and Neurons: In Search of the Common Chorus is a great discussion from World Science Fair 2009. Have you ever been driving along listening to the radio and suddenly a song plays and transports you to a different time or place? Have you ever wondered at the way music stirs your memories and emotion? Or have you ever stopped to think about how music, in its admittedly different forms, has been an integral part human of culture for as far back as we can study? Does music speak a particular primordial language that we all understand?
In this presentation Bobby McFerrin and three neuroscientists discuss the way the brain gets involved in music–the listening, physicality, participation and emotion. Essentially, music is a “whole nervous system activity”, involving many parts of the central nervous system that function nearly simultaneously. At one point in the talk pitch, tambre and rhythm defined and demonstrated. The researchers point out that certain intervals in music such as the minor third are prevalent in speech associated with negative emotions, but that no positive emotions are associated universally with a particular pitch.
The link to the full length presentation is here:Notes and Neurons.
But for fun today, get your whole brain involved and join Bobby McFerrin in this demonstration of the universality of the pentatonic scale.
[youtube http://www.youtube.com/watch?v=ne6tB2KiZuk&w=560&h=315]
I looked for a News and Views summary of the article, thinking that if the conclusions of the article were anything like what the title and abstract indicated, there must be an editorial summary. I wasn’t disappointed. Su and Tsai provided a nice summary of the paper and discussed some of the potential implications of the work (2). Continue reading “Hypomethylation in the Hippocampus: Can Age-Related Cognitive Decline in Mice Be Reversed by the Activity of One Gene?”
Welcome to the third installment of our series on cell-based assays; in this post we talk about treatment parameters for cell-based assays. Designed for the newbie to the world of cell-based assays, we have covered the topics of choosing your cell type and basic cell culture tips in the previous posts. In this post, we will discuss how decisions about test compound treatment: how much and how long can affect assay results and interpretation.
Continue reading “Considerations for Successful Cell-Based Assays III: Treatment Parameters”In a recent article published in Science Signaling, Yuangheng He and colleagues asked how the weak alkaline compound chloroquine (CQ) enhances the anti-inflammatory effects of synthetic glucocorticoids like dexamethasone, which are used to treat a host of inflammatory and autoimmune diseases. In the process they explored the intersection of lysosomal degradation pathways and glucocorticoid receptor signaling. For these investigations, they needed tools such as reporters and protein tags that allowed sensitive and accurate detection of events in real time in a variety of cells and systems.
The work is fascinating and removes the lysosome from its pigeon-hole description of garbage can (or recycling center) of the cell and places it in the center of cell signaling. The work also is fascinating because it takes a systems-view of a biological question: How is it that the drug chloroquine just happens to influence glucocorticoid signaling? To answer this question the authors employ an amazing array of techniques and technologies to ask questions in several systems under a many different conditions. The result is a work that explains a lot, but like all good science raises new questions for us to scratch our heads over.
Here I review this paper using “sketchnotes” with emphasis on the research techniques the researchers used. Continue reading “Of Lysosomes, Glucocorticoids and Inflammation”
Since the SCIO12 meeting, I have followed the #Iamscience discussion with interest. Reading the posts of others made me wonder, how did I become a scientist? When did I become a science writer? Where did the interest start? How did I end up where I am now? Continue reading “Whorl by Whorl, I Am Science”
This is the second in a series of blog posts covering topics to consider when designing and performing cell-based assays. In the first installment, we discussed the importance of choosing the right cell type for your assay. Here we will discuss how cell culture conditions affect cell-based assays.
Continue reading “Considerations for Successful Cell Based Assays II: Cell Culture Conditions”