Imagine you’re taking a refreshing night swim in the warm blue waters of Vieques in Puerto Rico. You splash into the surf and head out to some of the deeper waters of the bay, when what to your wondering eyes should appear, but blue streaks of light in water that once was clear. Do you need to get your eyes checked? Are you hallucinating? No! You’ve just happened upon a cluster of dinoflagellates, harmless bioluminescent microorganisms called plankton, that emit their glow when disturbed by movement. These dinoflagellates are known to inhabit waters throughout the world but are generally not present in large enough numbers to be noticed. There are only five ecosystems in the world where these special bioluminescent bays can be seen, and three of them are in Puerto Rico.
But you don’t have to travel to Puerto Rico or swim with plankton to see bioluminescence. There are bioluminescent organisms all over the world in many unexpected places. There are bioluminescent mushrooms, bioluminescent sea creatures—both large and small (squid, jellyfish, and shrimp, in addition to the dinoflagellates)—and bioluminescent insects, to name a few. Bioluminescence is simply the ability of living things to produce light.
Cervical cancer is a major health problem for women, and it is currently the fourth most common cancer in women globally (1). A worldwide analysis of cancer estimates from the Global Cancer Observatory 2018 database showed that cervical cancer disproportionally affects lower-resource countries, on the basis of their Human Development Index; it was the leading cause of cancer-related death in women in many African countries (1).
Infection by human papillomavirus (HPV), a double-stranded DNA virus, is the leading cause of cervical cancer. Many types of HPV have been identified, and at least 14 high-risk HPV types are cancer-causing, according to a World Health Organization (WHO) fact sheet. Of these types, HPV-16 and HPV-18 are responsible for 70% of cervical cancers and pre-cancerous cervical lesions. HPV infection is sexually transmitted, most commonly by skin-to-skin genital contact. Although the majority of HPV infections are benign and resolve within a year or two, persistent infection in women, together with other risk factors, can lead to the development of cervical cancer [reviewed in (2)].
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.
Today’s blog was written by guest blogger Katarzyna Dubiel, marketing intern in Cellular Analysis and Proteomics. Last updated 02/12/2021
Reporter gene assays have been critical for the study of a wide-range of biological questions, from regulation of gene expression to cellular signaling. While reporter gene assays constitute a large group of technologies, here we highlight the diversity of new discoveries enabled by highly quantitative and easily measured bioluminescent luciferase-based reporter assays. Below are our top picks of exciting research discoveries involving the Dual-Luciferase Reporter Assay format using firefly and Renilla luciferases.
Dual-Reporter Assays give scientists the ability to simultaneously measure two reporter enzymes within a single sample. In dual assays, the activity of an experimental reporter is correlated with the effect of specific experimental conditions, while the activity of a control reporter relays the baseline response, providing an essential internal control that reduces variability caused by differences in cell viability or transfection efficiency. The Nano-Glo® Dual-Luciferase® Reporter (NanoDLR™) Assay provides a choice of two sensitive reporters (firefly and NanoLuc luciferases) for use in dual-assay format. Both reporters give state-of-the-art functionality, raising the question “Which luciferase should be the primary reporter and which should be the control?”
Helping scientists design experiments and interpret data is what we do best at Promega Technical Services. This may mean spending time at the bench attempting to reproduce anomalous results or forming a team, perhaps with members of other departments, to brainstorm seemingly intractable experimental road blocks. Still, for many of us nothing surpasses the experience of meeting these same scientists face to face whether it be on their home turf or at a booth during a tradeshow. Continue reading “Running A Victory Lap For Promega’s Bioluminescence Technologies”
As part of my job I occasionally search the literature for papers citing use of Promega products in new or interesting ways. Any search on dual-luciferase reporters usually generates a lot of returns. A search for dual-luciferase on Highwire press generates over 700 articles from 2009 alone. So why are dual-luciferase reporter assays so widely used? Continue reading “Why Two Reporters are Better than One”
During my childhood, my family and I spent many a vacation in the Swiss Alps. From the mountain tops I used to look out into the horizon as far as the eye could see with peak upon peak stretching out into the distance. If I was lucky, I would have a map that allowed me to identify each peak, perhaps even distinguish the highest from the lowest and thus really get a sense that I understood the underlying topography. However, I quickly realized how little I actually knew about the vast, undulating Swiss countryside. What I had initially observed as a homogenous ‘mat’ of peaks stretching out into the horizon was in fact a rippling of deep valleys that would make an afternoon hike anything but a walk in the breeze.