Why You Don’t Need to Select a Wavelength for a Luciferase Assay

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. Continue reading “Why You Don’t Need to Select a Wavelength for a Luciferase Assay”

From Drug Screening to Agriculture to Cardiac Development, Dual Luciferase Reporters Bring You the Story

Today’s blog was written by guest blogger Katarzyna Dubiel, marketing intern in Cellular Analysis and Proteomics.

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. Continue reading “From Drug Screening to Agriculture to Cardiac Development, Dual Luciferase Reporters Bring You the Story”

STATs and ChIPs- Learning A Lesson Or Two About Transcriptional Activation

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. 

 
Looking back on these experiences I am struck by how closely they reflect the landscape of modern science— a broad mat of detailed knowledge with its own peaks of specialization.  I am reminded of the words of writer Bill Bryson who described science as “tens of thousands of people that do tiny, tiny things that all accrete into a larger body of knowledge” (1).  Continue reading “STATs and ChIPs- Learning A Lesson Or Two About Transcriptional Activation”