. 2008 Jul 16;28(29):7399–7411. doi: 10.1523/JNEUROSCI.1038-08.2008

Table 1.

Characteristics of GECIs and OGB-1 in vivo and in vitro

Probe	GFP variants^a	Functional sensor^b	Hill coefficient		K_D		Max. change		τ riseⁱ (40 Hz)^k	τ decay^j (40 Hz)^k
Probe	GFP variants^a	Functional sensor^b	In vitro^c	In vivo^d	In vitro^e	In vivo^f	In vitro^g	In vivo^h	τ riseⁱ (40 Hz)^k	τ decay^j (40 Hz)^k
YC3.3	ECFP/Citrine	CaM/M13	—	2.50	—	0.47 μm	—	67%	1.41 s	1.05 s
			—		(1.5 μm)	38 Hz	(100%)
YC3.60	ECFP/cpVenus	CaM/M13 E104Q	2.24	1.67	0.63 μm	0.36 μm	346%	136%	0.82 s	0.73 s
			(1.7)		(0.25 μm)	30 Hz	(560%)
YC2.60	ECFP/cpVenus	CaM/M13	—	1.84	—	0.40 μm	—	194%	—^k	5.24 s^k
			(2.4)		(0.04 μm)	32 Hz	(560%)
D3cpv	ECFP/cpVenus	CaM/M13 redesigned	0.63	0.96	0.66 μm	0.49 μm	190%	90%	0.68 s^k	1.96 s^k
			(0.74)		(0.53 μm)	41 Hz	(530%)
TN-L15	ECFP/Citrine	csTnC	1.29	2.59	0.72 μm	0.36 μm	82%	60%	0.81 s	1.49 s
			(0.89)		(1.2 μm)	30 Hz	(140%)
TN-XL	ECFP/cpCitrine	csTnC mut^l	1.90	2.74	2.20 μm	0.77 μm	252%	106%	0.59 s	0.20 s
			(1.7)		(2.5 μm)	65 Hz	(400%)
GC1.6	cpEGFP	CaM/M13	—	2.34	1.23 μm	0.64 μm	—	162%	1.38 s	0.45 s
			(3.8)		(0.15 μm)	54 Hz	(490%)
GC2	cpEGFP	CaM/M13	—	2.30	—	0.75 μm	—	156%	0.63 s	0.38 s
			(3.8)		(0.15 μm)	63 Hz	(490%)
OGB-1	—	BAPTA	0.97	1.48	0.24 μm	0.26 μm	11	316%	0.24 s^k	0.38 s^k
					(0.17 μm)	21 Hz	(14)

^a“GFP variants” lists the chromophores used in each indicator. cp, Circular permuted variant; EGFP, enhanced YFP; ECFP, enhanced CFP. ^b“Functional sensor” indicates the Ca²⁺ binding and interaction moieties. CaM, Calmodulin; csTnC, chicken skeletal muscle troponin C. Hill coefficients are listed for ^ccuvette measurements (Fig. 4) and ^din vivo measurements (Fig. 3). K_D values shown represent ^ecuvette measurements (Fig. 4) and ^fin vivo data (Fig. 3), respectively. Max. change represents (ΔR/R)_max or (ΔF/F)_max in ^gcuvette (uncorrected spectrophotometer measurements) for [Ca²⁺] = 39.8 μm and ^hamplitudes at 160 Hz in vivo (2PLSM measurements) as shown in Figure 4. ⁱτ rise and ^jτ decay were determined from single-exponential fits to rise and decay phases of indicator responses to 40 Hz. ^k20 Hz for YC2.60, D3cpv, and OGB-1. These values represent the properties of both the indicator and the specific fly lines. Values in parentheses represent literature values from original publications as cited in the text. ^lFour mutations within the C-terminal lobe of troponin C altered Mg²⁺ and Ca²⁺ binding properties.