Table 1.

FRETN values for EGFP derivatives coexpressed in single cells

Donor/acceptor pair*	Mean FRETN ± SD†	FRET extent, %‡
Gal-T2/GalNAc-T§	1.1 × 10−5  ± 5 × 10−6	49
Man II/Gal-T2	9.5 × 10−7  ± 6 × 10−7	17
Man II/GalNAc-T	8.0 × 10−7  ± 4 × 10−7	14
GalNAc-T/β1,4Gal-T	2.0 × 10−6  ± 5 × 10−7	17

^*In each pair, donor stands for the fusion to ECFP and acceptor for the fusion to EYFP. 

^† FRETN, FRET normalized for the expression levels of both donor and acceptor fluorophores. 

^‡ FRET extent was estimated by the formula FRETN = FRET1/( × ), which approximates to [bound]/[total donor] × [total acceptor] (11). 

^§ Value significantly higher (P < 0.02, Student's t test) than the other analyzed pairs. Results are mean of four independent experiments, each one resulting from the observation of 50 cells.