|Ex λ||Em λ||EC (M-1 cm-1)||QY||Brightness||pKa||Maturation (min)||Lifetime (ns)|
|% Normal Cells||OSER/NE ratio||Cell Type||Reference|
|62.5 ± 5.2 (10000 cells)||-||HeLa||Cranfill et al. (2016)|
|t1/2 (s)||Power||Light||Mode||In Cell||Fusion||˚C||Reference|
|30.3||20.0 (mW/mm2)||LED||Widefield||Saccharomyces cerevisiae||24.0||Lee et al. (2020)|
|58.0||20.0 (mW/mm2)||LED||Widefield||HEK239A||24.0||Lee et al. (2020)|
YFP3 possessed six mutations that resulted in an RRC almost fivefold greater than that of the parental pair. YFP3 also conferred a roughly threefold improvement in FRET relative to the fast-maturing Venus YFP. In an attempt to further enhance YFP3 brightness, the Venus mutations were combined with those of YFP3 to yield YFP for energy transfer (YPet). Though YFP3 exhibited slower folding relative to Venus, combining YFP3 and Venus mutations resulted in intermediate folding kinetics.
Nguyen and Daugherty (2005) reported the development of an improved FRET pair, YPet & CyPet, which had a sevenfold enhancement of the FRET signal. However, we discovered that most of the signal enhancement was due to enhanced dimerization of YPet to CyPet within the tethered construct, and was substantially reduced when we incorporated the monomerizing mutation previously developed to prevent the weak dimerization of GFP (Zacharias et al. 2002).