We’re big fans of optogenetics, a technology that allows researchers to activate individual cells using flashes of light. Typically it is brain neurons of rodents that are activated in optogenetic experiments, but other cells can also be targeted. This is done by introducing genetic material into animals to make certain of their cells reactive to light, while the other challenging piece is being able to deliver light deep inside the body. Fiber optic cables and embedded LEDs have made many experiments possible, but they still significantly limit the true capabilities of optogenetics. A team led by folks at Carnegie Mellon University have now created a molecular photosensitizer that can activate cells without a man-made light source.
The technology relies on fluorogen-activating proteins (FAP) that have been used in the past to track protein activity inside of cells. FAPs are genetically introduced, and when they interact with a specific fluorescent dye the combination glows. In the new study the researchers engineered a fluorescent dye that also produces singlet oxygen, which destroys proteins, when it interacts with FAP and light. This lets researchers selectively inactivate proteins that are being targeted.
The fluorescent dye produces light in the far-red or near-infrared spectrum, wavelengths that are best for light to penetrate through tissue. Moreover, the FAP-dye complex binds well to the target proteins, allowing accurate studies to be conducted.
Take a look at this example of the new photosensitizer being used inside a zebrafish:
Study in Nature Methods: A genetically targetable near-infrared photosensitizer…
Source: Carnegie Mellon University…
