Factors Influencing Compound Potency in Biochemical and Cellular Assays

Late in 2017, a group here at Promega launched an exciting new assay, the NanoBRET™ Target Engagement (TE) Intracellular Kinase Assay.

It’s easy for me to call this assay exciting; I was an editor on the project team. But judging by the reviews on the SelectScience® web site, others are excited about NanoBRET™ Target Engagement Intracellular Kinase Assay too.

A review of the NanoBRET TE Kinase assay from SelectScience® .

A review of the NanoBRET TE Kinase assay from SelectScience® .

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Millions of Pickles, Pickles in the Sea

For a few years beginning late in 2013, warmer ocean conditions in the eastern Pacific prompted the appearance of unexpected species and toxic algal blooms that devastated others. When temperatures cooled in 2017, the marine ecosystems seemed to be returning to normal. Except for the pyrosomes. Although these previously rare organisms did start to wash up on beaches during the periods of warming, they began to appear by the millions from Oregon to Alaska that spring.

Pyrosomes

Photo by Steven Grace.

Some combination of ideal conditions led pyrosomes to multiply, dominate the ocean surface and wash up on beaches along the US and Canadian Pacific Coasts. Pyrosomes typically exist offshore, far below the surface in warm, tropical waters all over the world. Their sudden proliferation in other areas is likely due to the warm, Pacific ocean “blob,” although atypical sea currents and changes in pyrosome diet have been offered as other possible explanations.

While the appearance of pyrosomes impeded the efforts of fisherman by clogging nets and filling hooks, greater ecological effects have yet to be observed. As we celebrate World Oceans Month, pyrosomes offer a mesmerizing example of the astounding biological diversity our oceans have to offer and, perhaps, a cautionary tale of the impact climate change can have on those marine lifeforms.

The pyrosome species common in the NE Pacific, Pyrosoma atlanticum, goes by a few other colorful names. Each name reveals something captivating about these creatures. Commonly called “sea pickles” due their size, shape and bumpy texture (like a transparent cucumber), these are not single organisms, but colonies formed by hundreds or thousands of individual multicellular animals call zooids.

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Questions of Genome Privacy and Protection

In April 2018, law enforcement officials announced the arrest of a suspect in the Golden State Killer case (New York Times ). Shortly after the announcement, those same law enforcement officers explained that detectives had used a public forensic genealogy web site to help identify the killer.

What does it mean when a law enforcement agency accesses a public genetic genealogy database to search for a suspect in a crime? Continue reading

New Recombinant Asp-N Mass Spec Protease: Improved Format and Reduced Price

Asp-N is a endoproteinase hydrolyzes peptide bonds on the N-terminal side of aspartic residues. The native form is isolated from Pseudomonas fragi. The majority of vendors currently provide a commercial product that consists of 2µg of lyophilized material in a flat bottom vial, and sold for $175–200 US. Formatting such a small amount of material in flat bottom vial can lead to inconsistent resuspension of the protease. Inconsistent working concentrations will lead to non-reproducible data. The current high price also prohibits large-scale use.

The new recombinant Asp-N protease is cloned from Stenotrophomonas maltophilia and expressed in E. coli. Recombinant Asp-N has similar amino acid cleavage specificity as compared to native Asp-N. Digestion of a yeast extract with native and recombinant Asp-N produces very similar results. Providing 10µg lyophilized material in V-shaped vial with a visible cake enables more consistent re-suspension resulting in reproducible data. Due to improved yields the list price is now approximately 40% less when compared to native enzyme.
Learn more about this new recombinant Asp-N protease.

How to Take Care of Your Pipettes

what not to do with your pipettes

Pipettes are such a routine part of everyday life in the lab that it can be easy to take them for granted.  Their accuracy is vital, and there are many things we can adopt as best practices for success. Here are a few tips (no pun intended) gathered from around the Web by Kim Steinhauser of the Promega Metrology Department–the group charged with keeping our pipettes and other lab equipment functional and accurate. Continue reading

Musings on the 2018 International Forum on Consciousness

Held May 2018, Means and Metrics for Detecting and Measuring Consciousness was designed to explore emerging technologies for studying the phenomenon of consciousness, including research related to sleep, wakefulness, altered states, focused attention and coma.  We asked the question: How might our ability to better measure consciousness create opportunities to improve human function, resolve disease states and keep the mind and brain throughput all stages of life?

We’re grateful for the ideas and insights, the personal stories, shared by Christof Koch, Melanie Boly, Franz Vollenweider, Heather Berlin, Nicholas Schiff and Thupten Jinpa, as well as for the sound and movement experiences provided by Lisa O’Connor and Laura Flanagan.  (Videos of their talks can easily be accessed on-line: https://www.btci.org/events-symposia-2018/international-forum-on-consciousness/archive/2018-videos-2/ )

Our sense is that those who joined us (250+ attendees) left both more knowledgeable and inspired.  Comments from participants illustrate their appreciation for presenters’ insights: Continue reading

High-Throughput Purification with Experts Included

Implementing automated nucleic acid purification or making changes to your high-throughput (HT) workflow can be complicated and time-consuming. There are also many barriers to success such as challenging samples types and maintaining desirable downstream results that can add to the stress, not to mention actually getting the robotic instrumentation to do what you want it to. All of this makes it easy to understand why many labs avoid automating or own expensive instrumentation that goes unused. Continue reading

Will This Kit Work with My Sample Type?

Whether you are working with cells, tissues or blood—making sure you use the correct assay system is critical for success.

In Technical Services, we frequently answer questions about whether a kit will work with a particular type of sample. An easy way to find out if other researchers have already tested your sample type of interest is to search a citation database such as Pub Med for the name of the kit and your specific sample type. We also have a searchable peer-reviewed citations database on our web site for papers that specifically cite use of our products. And on many of our product pages, you can find a list of papers that cite use of those products. In Technical Services, we are happy to help you in this search and let you know if scientists here at Promega have tested a particular application or sample type. This information provides a good starting point to optimize your own experiments.

One common question is “can the Caspase-Glo® Assays be used with tissue homogenates?” While Promega has not tested the Caspase-Glo® Assays with tissue homogenates, scientists outside of Promega have used the assays with tissue homogenates with success. As with almost all of our kits, Resources are provided on the catalog page including a list of Citations. As an example, here is a link to the Citations for the Caspase-Glo® 3/7 Assay Systems. We also have an article highlighting a citation on detecting caspase activities in mouse liver. A variety of lysis buffers have been used to make tissue homogenates for this application. To avoid nonspecific protein degradation, it is useful to include a protease inhibitor cocktail in the lysis buffer. The use of protease inhibitors doesn’t usually affect our assay chemistries. Additionally, many commercially available protease inhibitor sets can be used that do not contain caspase inhibitors. It is important to consider the specificity of the kit being used and include proper controls to ensure that the luciferase reaction is performing as expected. For more information on citations and example protocols, feel free to contact us here at Technical Services and we can help get you started with your sample type.

Kicking Off Summer with Some Cookout Favorites

In the United States, the last Monday of May is Memorial Day, a national holiday in which we honor those who have given their lives in service to the country. For those of us living in Wisconsin, Memorial Day is also usually preceded by the first truly warm weekend of summer. So as families remember their loved ones, they gather together to create new memories in parks and backyards, around picnic tables or on grassy lawns–beginning the summer season of cookouts, picnics and bar-b-ques.

Here at Promega we love a good cookout too. So a few of us have cobbled together some of our favorite summer recipes to share with you. Do you have a favorite summer recipe? Share it in the comments below.  (Please note metric conversions are approximate and have not been tested.) Continue reading

When School is just a Memory: Science after Graduation

Happy graduation! Whether you graduated last week or twenty years ago, the experience is roughly the same. As soon as you arrive on the far side of the stage, empty diploma folder under your arm, hand still sticky from the Dean’s sweaty handshake, the reality of post-academic life sets in. Perhaps grad school is on the horizon for some and others might be busy prepping for med school. For some of us, though, our years of formal education end after four and we run off to rejoice in our newfound freedom. No more exams, group projects, late nights writing papers, disapproving professors, supervisors and mentors – done with that life forever! We didn’t even bother with the GRE, MCAT, LSAT or a single “Why [insert school]” essay. Now it’s off to enjoy the Real World, which will definitely be better than college.

I’ve found, in my one year of post-college life, that sometimes you can miss academic life. You’ll occasionally look back and think, “I didn’t know how good I had it.” In particular, those of us with a pure love of learning can find ourselves unsatisfied with our prospective learning opportunities or lack thereof. We spent college soaking up mountains of knowledge–and not just from textbooks. University life gives you access to free talks from eminent thought leaders, unrestricted access to myriad scientific journals, and plenty of people around who are eager to argue about that day’s lecture in Cell Biology or Neuroscience. After college, it’s tough to fill that void.

I work at Promega (obviously), a biotech company, so I still have access to journals and there are plenty of brilliant scientists around me. However, I’m still looking for more opportunities to learn and grow. I may be out of school, but the love of science never goes away. Here are a few of my tips for everyone receiving their hard-earned science degree this spring.

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