Abstract: Femtosecond lasers at fixed wavelengths above 1,000 nm are powerful, stable and inexpensive, making them promising sources for two-photon microscopy. Biosensors optimized for these wavelengths are needed for both next-generation microscopes and affordable turn-key systems. Here we report jYCaMP1, a yellow variant of the calcium indicator jGCaMP7 that outperforms its parent in mice and flies at excitation wavelengths above 1,000 nm and enables improved two-color calcium imaging with red fluorescent protein-based indicators.

Authors: Manuel Alexander Mohr, Daniel Bushey, Abhi Aggarwal, Jonathan S. Marvin, Jeong Jun Kim, Emiliano Jimenez Marquez, Yajie Liang, Ronak Patel, John J. Macklin, Chi-Yu Lee, Arthur Tsang, Getahun Tsegaye, Allison M. Ahrens, Jerry L. Chen, Douglas S. Kim, Allan M. Wong, Loren L. Looger, Eric R. Schreiter & Kaspar Podgorski