Every Friday on Twitter, scientists from around the world post their favorite glowing pictures on Twitter using the hashtag #FluorescenceFriday. So, what is fluorescence? And how can you study it in your classroom?
First, fluorescence is defined as “the emission of light by a material (molecule, protein, chemical) that has absorbed electromagnetic radiation.” What does this mean? Basically, when light or other energy waves is focused on a substance, it will produce and release a different (usually lower) wavelength of energy. Many times, fluorescent emissions of light are within the visible range, meaning that we can see it with the naked eye. For example, the green fluorescent protein (GFP) is a protein that absorbs light in the blue range and emits light in the green range without the need for additional cofactors or chemicals. Animals, minerals, and vegetables (ok, fungi) naturally exhibit fluorescence, making for an interesting, glowing world!
#FluorescenceFriday encourages researchers who are studying fluorescence or using it as a tool to study biology to share the results of their experiments, specifically the amazing ones that glow! Here are a few of my favorites:
We’ve written a bit about fluorescence here on the blog if you want to learn more. Plus, we have several experiments that let you explore this phenomenon in the lab!
- Exploring Biotechnology with GFP: Four experimental modules are combined into one experiment to provide a comprehensive biotechnology exploration focusing on GFP. Bacterial cells are transformed to express GFP. The transformed cells are then grown and the GFP is purified by column chromatography. Finally, the purity of the protein fractions are analyzed by SDS polyacrylamide electrophoresis.
- Transformation of E. coli with Green Fluorescent Protein (GFP): In this experiment, students will explore the biological process of bacterial transformation using E. coli and plasmid DNA. At the end of the activity, students will have experience observing and analyzing acquired traits (ampicillin resistance and fluorescence) as exhibited by transformed bacterial cells.
- DNA/RNA Microarrays: Membrane microarray technology is enabling scientists to screen large numbers of samples in one assay. This technology has led to cost savings by reducing the sample size, while saving time and yielding accurate results. Students will apply simulated DNA and RNA samples to a membrane to screen for positive and negative samples.
- Lighting Up Life: Expression of GFP in C. elegans: Scientists can directly manipulate an organism’s genome to produce a phenotype using engineered genes called transgenes. In this experiment, students will use fluorescent microscopy and PCR to analyze C. elegans (nematodes) that have been engineered to express GFP.