Table 1.

Fluorescence resonance energy transfer (FRET) sensors for ions and metabolites

Class	Analyte	Sensor	Selected references
Pentose	Arabinose	FLIPara	Kaper et al. (2008)
	Ribose	FLIPrib	Lager et al. (2003)
Hexose	Glucose	FLIPglu	Deuschle et al. (2005b); Takanaga et al. (2008)
	Galactose	FLIPglu	Deuschle et al. (2005b); Takanaga et al. (2008)
Disaccharide	Maltose	FLIPmal	Kaper et al. (2008)
	Sucrose	FLIPsuc	Lager et al. (2006); Chaudhuri et al. (2008)
Amino acid	Glutamate	FLIPe	Deuschle et al. (2005b); Okumoto et al. (2005); Hires et al. (2008)
	Arginine		Bogner & Ludewig (2007)
	Tryptophan	FLIPW	Kaper et al. (2007)
Nucleobase	Purine	FLIPpur	A. Schmidt et al. (unpublished)
Polyamine	Polyamines	FLIPpa	S. Lalonde & W. B. Frommer (unpublished)
Ions	Calcium	Cameleon, TN-XL	Miyawaki et al. (1997); Romoser et al. (1997); Garaschuk et al. (2007)
	Phosphate	FLIPphos	Gu et al. (2006)
	Protons	pHluorin, Ptsilosarcus GFP	Miesenbock et al. (1998); Schulte et al. (2006)
	Halides	Clomelion	Jose et al. (2007); Markova et al. (2008)