ReaChR-Strep full length protein-synthetic nanodisc

ReaChR (Red-activatable Channelrhodopsin) is a genetically engineered, red-shifted channelrhodopsin developed for optogenetic applications. It was first reported by John Y. Lin and colleagues in 2013 (doi:10.1038/nn.3502) as an improved microbial opsin capable of efficiently activating neurons with orange to red light (approximately 590–630 nm). Compared with conventional Channelrhodopsin-2 (ChR2), which requires blue light for activation, ReaChR exhibits a substantially red-shifted excitation spectrum, allowing deeper light penetration into biological tissues because red light experiences less scattering and lower absorption by hemoglobin. As a result, ReaChR enables less invasive optical stimulation of deep brain regions and has become one of the most widely used red-light-responsive optogenetic actuators.