Posted by Nathaniel Sperka on 18th Oct 2026
Back in 2011, I was contacted by a researcher at the UCSF Cyster Lab who introduced herself as Betsy Gray. She asked for a fiber-coupled Violet LED. Little did I know that this would become one of our most popular setups, used across labs for the photoconversion of photoconvertible proteins.
If you work with photoconvertible fluorescent proteins like KikGR and Kaede, you already know how useful they are for tracking cell movement and studying protein dynamics. I am not a scientist, so I had no idea what this would be used for back then—but thanks to that initial inquiry, we helped configure a setup that researchers have repeatedly requested ever since.
The method she used was originally described in the paper CXCR4 promotes B cell egress from Peyer’s patches. The setup back then included an FC-LED-415, which at the time we called the “silver-LED” because of the silver enclosure. The fiberoptic was a 1500um high-NA fiber connected to a 1/2-inch collimator. The light was delivered to the animal tissue for a few minutes, with the tissue covered by an aluminum foil shield featuring a small hole in it.
Since then, there have been a few upgrades. Many researchers transitioned to the powerful 405nm FC-LED-405, which delivers more than double the optical power of the older 415nm model.
More recently, a team at Memorial Sloan Kettering Cancer Center did side-by-side testing of the FC-LED-405 and the Ultra High Power Optogenetics-LED-Violet. This is also a 405nm fiber-coupled LED, but it features active cooling and significantly higher power than the passively cooled FC-LED. Following those tests, researchers have increasingly ordered the Prizmatix Optogenetics Violet LED systems for these experiments to achieve faster, more thorough photoconversion. (Feel free to contact me if you'd like to see their data!)
If you are looking to put together a similar rig, here is the standard parts list used for these setups:
Question: What about photoconversion in a microwell plate or under a microscope objective?
Answer: We have solutions for these applications!
Have a question or looking to configure a system for your lab? Contact me—I am always happy to help you find the best setup for your research.