A sensitive orange fluorescent calcium ion indicator for imaging neural activity (opens in new tab)

Genetically encoded calcium indicators (GECIs) are vital tools for fluorescence-based visualization of neuronal activity with high spatial and temporal resolution. However, current highest-performance GECIs are predominantly green or red fluorescent, limiting multiplexing options and efficient excitation with fixed-wavelength femtosecond lasers operating at 1030 nm. In an effort to overcome these limitations, we developed OCaMP, an orange fluorescent GECI engineered from O-GECO1 through targe...