TABLE 3.

Non-GCaMP-based genetically encoded calcium indicators, including GECOs and camgaroos.

Class	Indicator	Emission wavelength (nm)	Description	References
GECO	G-GECO1-1.2	∼512	Better than GCaMP3 for monitoring spontaneous Ca2 + oscillations. Higher fluorescence than GCaMP3. pH-sensitive.	Zhao et al., 2011
	B-GECO1	446	Suited for multichromatic imaging. pH-insensitive compared to G-GECOs. Interference with mitochondrial autofluorescence.	Zhao et al., 2011
	R-GECO1	∼600	Greater dynamic range and higher calcium binding affinity than RCaMP. Susceptible to artifact-induced excitation with blue and green light.	Zhao et al., 2011; Akerboom et al., 2013
	NIR-GECO2/2G	685/40	Near-infrared calcium indicators susceptible to infrared light-induced activation. Lower brightness and slower kinetics than standard green and red GECIs.	Qian et al., 2020
	GEX-GECO1	∼510	Fast kinetics, large dynamic range.	Zhao et al., 2011
	GEM-GECO1	511/455	Good signal range, mitochondrial autofluorescence does not interfere with its activity.	Zhao et al., 2011
	jRGECO1a	630	Faster than RCaMP.	Dana et al., 2016
Camgaroos	Camgaroo-1	513	Unable to detect single APs. Exhibits slower kinetics than latest GCaMP versions.	Baird et al., 1999; Barth, 2007
	Camgaroo-2	535	Unable to detect single APs. Exhibits slower kinetics than latest GCaMP versions.	Griesbeck et al., 2001; Barth, 2007