All Aglow in the Ocean Deep


Fascinating bioluminescent creature floating on dark waters of the ocean. Polychaete tomopteris.

Today’s blog comes to you from the Promega North America Branch Office.

In nature, the ability to “glow” is actually quite common. Bioluminescence, the chemical reaction involving the molecule luciferin, is a useful adaptation for many lifeforms. Fireflies, mushrooms and creatures of the ocean deep use their internal lightshows to cope with a variety of situations. Used for hunting, communicating, ridding cells of oxygen, and simply surviving in the darkness of the ocean depths, bioluminescence is one of nature’s more flashy, and advantageous traits.

In new research published in April in the journal Scientific Reports, MBARI researchers Séverine Martini and Steve Haddock found that three-quarters of all sea animals make their own light.  The study reviewed 17 years of video from Monterey Bay, Calif in oceans that descended to 2.5 miles, to determine the commonality of bioluminescence in the deep waters.

Martini and Haddock’s observations concluded that 76 percent off all observed animals produced some light, including 97 to 99.7 cnidarians (jellyfish), half of fish, and most polychaetes (worms), cephalopods (squid), and crustaceans (shrimp).

Most of us are familiar with the fabled anglerfish, the menacing deep-sea creature known for attracting ignorant prey with a glowing lure attached to their head. As you descend below 200 meters, where light no longer penetrates, you will be surprised at the unexpected color display of the oceans’ sea life. Bioluminescence is not simply an exotic phenomenon, but an important ecological trait that the oceans’ sea creatures have wholeheartedly adopted to cope with complete darkness. Continue reading

Why wait ? Sample prep/protein digestion in as little as 30 minutes!

While many proteases are used in bottom-up mass spectrometric (MS) analysis, trypsin (4,5) is the de facto protease of choice for most applications. There are several reasons for this: Trypsin is highly efficient, active and specific. Tryptic peptides produced after proteolysis are ideally suited, in terms of both size (350–1,600 Daltons) and charge (+2 to +4), for MS analysis. One significant drawback to trypsin digestion is the long sample preparation times, which typically range from 4 hours to overnight for most protocols. Achieving efficient digestion usually requires that protein substrates first be unfolded either with surfactants or denaturants such as urea or guanidine. These chemical additives can have negative effects, including protein modification, inhibition of trypsin or incompatibility with downstream LC-MS/MS. Accordingly, additional steps are typically required to remove these compounds prior to analysis.

To shorten the time required to prepare samples for LC-MS/MS analysis, we have developed a specialized trypsin preparation that supports rapid and efficient digestion at temperatures as high as 70°C. There are several benefits to this approach. First, proteolytic reaction times are dramatically shortened. Second, because no chemical denaturants have been added, off -line sample cleanup is not necessary, leading to shorter preparation times and diminished sample losses.

The Rapid Digestion trypsin protocols are highly flexible. They can accommodate a variety of additives including reducing and alkylating agents. There are no restrictions on sample volume or substrate concentrations with these kits. Furthermore, the protocol is simple to follow and requires no laboratory equipment beyond a heat block. Digestion is achieved completely using an in-solution approach, and since the enzyme is not immobilized on beads, the protocol does not have strict requirements for rapid shaking and off -line filtering to remove beads.

In addition to the benefits of this flexibility, we also developed a Rapid Digestion–Trypsin/Lys-C mixture. Like the Trypsin/Lys-C Mix previously developed to prepare maximally efficiently proteolytic digests, particularly for complex mixtures, Rapid Digestion–Trypsin/Lys C is ideally suited for studies that require improved reproducibility across samples.


Surfing the Light Waves: Shrimp, Coral, Turtles and Other Fluorescent Organisms

A branching torch coral, Euphyllia glabrescens.

Have you ever walked on a beach and noticed that the waves seem to glow as they roll onto shore? Perhaps you have seen fish or jellyfish that glow in the dark, or maybe you’ve chased fireflies in your backyard or on a camping trip. These are all forms of luminescence (the production of light without adding heat), but the manner that these organisms produce their light can be quite different. Continue reading

In Healthy Eating Less is More: The Science Behind Intermittent Fasting

Mix a love of eating with a desire to live a long, healthy life what do you get? Probably the average 21st century person looking for a way to continue enjoying food despite insufficient exercise and/or an age-related decline in caloric needs.

Enter intermittent fasting, a topic that has found it’s way into most news sources, from National Institutes of Health (NIH) and Proceedings of the National Academy of Sciences publications to WebMD and even the popular press. For instance, National Public Radio’s “The Salt” writers have tried and written about their experiences with dietary restriction.

While fasting has enjoyed fad-like popularity the past several years, it is not new. Fasting, whether purposely not eating or eating a restricted diet, has been practiced for 1,000s of years. What is new is research studies from which we are learning the physiologic effects of fasting and other forms of decreased nutrient intake.

You may have heard the claims that fasting makes people smarter, more focused and thinner? Researchers today are using cell and animal models, and even human subjects, to measure biochemical responses at the cellular level to restricted nutrient intake and meal timing, in part to prove/disprove such claims (1,2). Continue reading

Biotech Manufacturing: A Good Machinist is Critical for Your Laboratory Reagents

Travis Beyer, Machinist Technician, at the CNC milling machine in the Promega machine shop.

Travis Beyer, Machinist Technician, at the CNC milling machine in the Promega machine shop.

It can be easy to forget that Promega is a manufacturing business. The company’s cGMP Feynman Center on the Madison campus has been described as looking more like a retreat than a factory. But hidden within the well-designed walls of Feynman, as well as in other facilities on campus, technicians operate hundreds of machines that manufacture, dispense and package Promega reagents day in and day out. Keeping those high-tech machines running at peak performance is critical, requiring immense skill, precision and even artistry. That’s where Promega Machinist Technician Travis Beyer comes in.

“I get to make stuff,” says Travis who is not afraid to show his enthusiasm for his craft while describing the best part of his job. “There’s a product at the end of the day. Plus I get to support science, and make things that support people’s lives. That’s cool.”

 I get to make stuff. There’s a product at the end of the day. Plus I get to support science, and make things that support people’s lives. That’s cool.

The da Vinci Center, another artfully designed building on the Madison campus, houses the Promega machine shop where Travis does his work designing or improving on parts for newer manufacturing equipment or reverse engineering broken or worn parts no longer available for older equipment that still serves its purpose. He makes every machine part imaginable from drive shafts to sensor brackets to filling forks, and his work is critical to manufacturing businesses like Promega, where a downed piece of equipment can cause costly production delays.

An example of a machine part that Travis designs or reverse engineers and then builds to keep Promega manufacturing moving smoothly.

An example of a machine part that Travis designs or reverse engineers and then builds to keep Promega manufacturing moving smoothly.

As he explains, not many manufacturing companies the size of Promega have a fully capable machine shop. They usually send out their work, meaning longer lead times and more expense. But, as its distinctive architecture suggests, Promega is not like many other companies. Continue reading

Making BRET the Bright Choice for In vivo Imaging: Use of NanoLuc® Luciferase with Fluorescent Protein Acceptors

13305818-cr-da-nanoluc-application_ligundLive animal in vivo imaging is a common and useful tool for research, but current tools could be better. Two recent papers discuss adaptations of BRET technology combining the brightness of fluorescence with the low background of a bioluminescence reaction to create enhanced in vivo imaging capabilities.

The key is to image photons at wavelengths above 600nm, as lower wavelengths are absorbed by heme-containing proteins (Chu, J., et al., 2016 ). Fluorescent protein use in vivo is limited because the proteins must be excited by an external light source, which generates autofluorescence and has limited penetration due to absorption by tissues. Bioluminescence imaging continues to be a solution, especially firefly luciferase (612nm emission at 37°C), but its use typically requires long image acquisition times. Other luciferases, like NanoLuc, Renilla, and Gaussia, etc. either do not produce enough light or the wavelengths are readily absorbed by tissues, limiting their use to near- surface imaging.

The two papers discussed here illustrate how researchers have combined NanoLuc® luciferase with a fluorescent protein to harness bioluminescent resonance energy transfer (BRET) for brighter in vivo imaging reporters. Continue reading

Don’t Let These Three Common Issues Hurt Your Luminescent Assay Results

4621CAThere is a lot riding on your luminescent assay results. Each plate represents precious time, effort and resources. Did you know that there are three things about your detection instrument that can impact how much useful information you get from each plate?  Instruments with poor sensitivity may cause you to miss low-level samples that could be the “hit” you are looking for.  Instruments with a narrow detection range limit the accuracy or reproducibility you needed to repeat your work.  Finally, instruments that let the signal from bright wells spill into adjacent wells allow crosstalk to occur and skew experimental results, costing you time and leading to failed or repeated experiments. Continue reading

Researchers Gather at Promega Madison Campus for Annual Stem Cell Symposium

stemcell header

Since the derivation of human-derived embryonic stem cells (ES cells) in the 1990’s, the world of stem cell biology and engineering has proceeded at an amazing pace. The isolation pluripotent cells (iPS) cells that have most of the properties of embryonic stem cells from somatic tissues has been possible for nearly a decade. Engineered human cells, tissues, and organ-like structures are becoming a reality and may soon play a part in treating diseases. ES and iPS cells are teaching us much about how cells become specialized during normal development and the pathologies that result when those specialization decisions go wrong.

At the 12th Annual Wisconsin Stem Cell Symposium held at the BioPharmaceutical Technology Center institute, leading researchers from around the world will be gathered to discuss the latest progress, roadblocks and issues around Engineering Cells and Tissues for Discovery and Therapy.

The Symposium is co-coordinated by the Stem Cell & Regenerative Medicine Center at the University of Wisconsin-Madison and the BioPharmaceutical Technology Center Institute and is open to the public. Registration is $100.00 ($50.00 for students and post-doctoral researchers). The Symposium will be held at Promega Corporation’s BioPharmaceutical Technology Center, 5445 E. Cheryl Parkway, Fitchburg, WI.

Topics to be discussed include: Continue reading

Making the Switch from FRET to BRET: Applications of NanoLuc® Luciferase with Fluorescent Protein Acceptors for Sensing Cellular Events

A Bioluminescent Alternative

Fluorescence resonance energy transfer (FRET) probes or sensors are commonly used to measure cellular events. The probes typically have a matched pair of fluorescent proteins joined by a ligand-binding or responsive protein domain. Changes in the responsive domain are reflected in conformational changes that either bring the two fluorescent proteins together or drive them apart. The sensors are measured by hitting the most blue-shifted fluorescent protein with its excitation wavelength (donor). The resulting emission is transferred to the most red-shifted fluorescent protein in the pair, and the result is ultimately emission from the red-shifted protein (acceptor).

As pointed out by Aper, S.J.A. et al. below, FRET sensors face challenges of photobleaching, autofluorescence, and, in the case of exciting cyan-excitable donors, phototoxicity. Another challenge to using FRET sensors comes when employing optogenetic regulators to initiate the event you wish to monitor. Optogenetic regulators respond to specific wavelengths and initiate signaling. The challenge comes when the FRET donor excitation overlaps with the optogenetic initiation wavelengths. Researchers have sought to alleviate many of these challenges by exchanging the fluorescent donor for a bioluminescent donor, making bioluminescence resonance energy transfer (BRET) probes. In the three papers described below, the authors chose NanoLuc® Luciferase as the BRET donor due to its extremely bright signal. Continue reading

Widening the Proteolysis Bottleneck: A New Protein Sample Preparation Tool

The poster featured in this blog provides background information and data on development of Rapid Digestion-Trypsin.

The poster featured in this blog provides background information and data on development of Rapid Digestion-Trypsin.

Improvements in Protein Bioprocessing

As more and more protein-based therapeutics enter research pipelines, more efficient protocols are needed for characterization of protein structure and function, as well as means of quantitation. One main step in this pipeline, proteolysis of these proteins into peptides, presents a bottleneck and can require optimization of multiple steps including reduction, alkylation and digestion time.

We have developed a new trypsin reagent, Rapid Digestion–Trypsin, that streamlines the protein sample preparation process, reducing the time to achieve proteolysis to about 1 hour, a remarkable improvement over existing overnight sample preparation times.

How Does it Work?

With this new trypsin product, proteolysis is performed at 70°C, incorporating both denaturation and rapid digestion. The protocol can be used with multiple protein types, including pure proteins and complex mixtures, and is compatible with digestion under native, reduced or nonreduced conditions.

Continue reading