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:

• Light Source: FC-LED-405 or Ultra High Power Optogenetics-LED-Violet
• Fiberoptic Patch Cord: 1500um core (NA = 0.5) SMA Connectors  (Note: a 1000um fiber optic works great too)
• Delivery Optics: 1/2” Collimator

Question: What about photoconversion in a microwell plate or under a microscope objective?

Answer: We have solutions for these applications!

• Microwell Plate & Petri Dish Illumination: For bulk photoconversion across entire cell populations, the Prizmatix UHP-T-405-MP delivers high-intensity violet light designed specifically to cover multi-well plates (like 96-well, 24-well, or 6-well formats) and petri dishes evenly without edge drop-off.

• In-Incubator Long-Term Tracking: When you need to photoconvert cells without disturbing controlled culture conditions, the Prizmatix UHP-F system paired with a specialized reflective collimator and beam-shaping optics delivers a uniform light field directly inside your incubator or CO2 chamber—protecting delicate electronics while keeping your cells in their optimal environment.

• Microscope-Coupled Photoconversion: For single-cell or sub-cellular target regions, we offer the Ultra high-power UHP-T-405-SR Microscope LED that couple directly to the epi-fluorescence or field port of major microscope brands (Nikon, Olympus, Leica, Zeiss). They deliver an intense, controllable pulse of 405nm light right down the optical path for rapid live-cell photoconversion. This modular LED can also be used with fiber optics via a simple fiber coupler adapter.

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.