Posted On: Sunday, May 25, 2014
Dr. Martha Marvin of Williams College is using the Stereo Microscope Fluorescence Adapter to look at transgenic zebrafish (Dania rerio) with several different fluorescent proteins (see reference at bottom of page). She recently wrote:
“We have fish with blue fluorescent (BFP) hearts that also up-regulate GFP in response to stress. To sort the transgenics we look at blue fluorescence. That didn’t work well with the violet filter, but if we illuminate with violet and view through the blue filter it’s quite easy to see.”
The blue fluorescence came from Evrogen TagBFP. Based on the published spectra for this fluorophore one would expect our Violet light + filter set (400 – 415nm excitation, 460nm longpass emission) to be the best choice for exciting and capturing the most fluorescence. Apparently in this case there was some general blue fluorescence in the background that made it hard to reliably distinguish the blue fluorescence of the hearts. This background fluorescence did not pass through the yellow filter that comes with the Royal Blue filter set, while enough of the BFP emission did, resulting in improved contrast.
Reference – Krug, R. G., Poshusta, T. L., Skuster, K. J., Berg, M. R., Gardner, S. L., & Clark, K. J. (2014). A transgenic zebrafish model for monitoring glucocorticoid receptor activity. Genes, Brain and Behavior, 13(5), 478-487.