Table 2.

The BRET-based bioluminescence system.

Name	Bioluminescence Donor	Fluorescence Acceptor	Luciferin	λmax (nm)	Note	Refs.
BAF-Y	RLuc	EYFP	coelenterazine	525	7-fold brighter than RLuc	[26]
eBAF-Y	RLuc8	EYFP	coelenterazine	525	25-fold brighter than RLuc	[26]
BRET1	RLuc	eYFP	coelenterazine	527		[27]
BRET2	RLuc	GFP2	DeepBlueC	410		[28]
BRET3	RLuc8	mOrange	coelenterazine	564		[29]
BRET3.1	RLuc8	mOrange	coelenterazine-v	564	Decreased BRET efficiency	[30]
BRET4	RLuc8	TagRFP	coelenterazine	584		[31]
BRET5	RLuc8.6	TagRFP	coelenterazine	584		[30]
BRET6	RLuc8.6	TurboFP	coelenterazine	635		[30]
BRET6.1	RLuc8.6	TurboFP	coelenterazine-v	635	Increased BRET efficiency	[30]
-	RLuc8	iRFP670	methoxy-eCoelenterazine	643		[32]
-	RLuc8	iRFP720	methoxy-eCoelenterazine	702		[32]
iRFP-RLuc8.6-535SG	RLuc8.6-535 (S257G)	iRFP	BBlue2.3	717		[33]
Nano-lantern (YNL)	RLuc8∆N3(S257G)	Venus∆C10	coelenterazine	530	2.9-fold brighter than eBAF-Y	[34]
CNL	RLuc8∆N3 (S257G)	mTurquoise2∆C10	coelenterazine	470		[35]
ONL	RLuc8.6-535∆N3	mKusabiraOrange2	coelenterazine	560		[35]
-	NLuc	YFP	furimazine	530		[36]
-	NLuc	Venus	furimazine	535		[37]
-	NLuc	mKate2	furimazine	633		[38]
CeNL	NLuc∆N3	mTurquoise2∆C10	furimazine	475		[39]
GeNL	NLuc∆N5	mNeonGreen∆C10	furimazine	520		[39]
YeNL	NLuc∆N4	Venus∆C12	furimazine	530		[39]
ReNL	NLuc∆N5	tdTomato∆C9	furimazine	585		[39]
OeNL	NLuc	mKOκ	furimazine	565		[39]
GpNLuc LumiFluor	NLuc	EGFP	furimazine	509	45-fold brighter than Nano-lantern	[40]
OgNLuc LumiFluor	NLuc	LSS mOrange	furimazine	572		[40]
Antares	NLuc	CyOFP1	furimazine, hydrofurimazine, or fluorofurimazine	583	Similar or higher brightness in vivo compared to AkaBLI with hydrofurimazine, or fluorofurimazine	[41,42]
Antares2	teLuc	CyOFP1	diphenylterazine	583	Additional 35–90% signal increase over teLuc,	[24]
-	LumiLuc (teLuc with E4G, L18Q, S19A, V27L, S28T, G67C, G71A, N85D, V90A, R112Q, V119K, and K136T mutations)	mScarlet	8pyDTZ	600		[25]
-	FLuc	DsRed	d-luciferin	583		[43]
-		mCherry	d-luciferin	610		[44]
-		mKate	d-luciferin	635		[45]
-		Cy3.5	d-luciferin	596		[46]
-	Ppy RE10	Alexa Fluor 680	d-luciferin	705	BRET ratio: 34.0	[47]
-		Alexa Fluor 750	d-luciferin	783	BRET ratio: 4.0	[47]
-	NLuc	Alexa Fluor 488	furimazine	525	Via SNAP-tag or HaloTag7	[48]
-		TMR	furimazine	585	Via SNAP-tag or HaloTag7	[48]
-		CPY	furimazine	645	Via SNAP-tag or HaloTag7	[48]
		SiR	furimazine	670	Via SNAP-tag or HaloTag7	[48]
-	RLuc8	QD605	coelenterazine	605	BRET ratio: 0.70	[49]
-		QD655	coelenterazine	655	BRET ratio: 1.2	[49,50,51]
-		QD705	coelenterazine	705	BRET ratio: 2.3	[49]
-		QD800	coelenterazine	800	BRET ratio: 1.32	[49]
-	NLuc	QD705	furimazine	705	BRET ratio: 13.3	[52]