|Ex λ||Em λ||EC (M-1 cm-1)||QY||Brightness||pKa||Maturation (min)||Lifetime (ns)|
|% Normal Cells||OSER/NE ratio||Cell Type||Reference|
|14.0 (70 cells)||-||U-2 OS||Bindels et al. (2016)|
|t1/2 (s)||Power||Light||Mode||In Cell||Fusion||˚C||Reference|
|349.0||Bajar et al. (2016)|
mRuby3 was derived from mRuby2 with the following mutations: N33R/M36E/T38V/K74A/G75D/M105T/C114E/H118N/Q120K/H159D/M160I/S171H/S173N/I192V/L202I/M209T/F210Y/H216V/F221Y/A222S/G223N
amino acid numbers relative to eqFP611. show relative to mRuby2
Negligible photochromic behavior was measured for the mScarlet variants, while TagRFP-T, mRuby2, mRuby3 and mApple showed 15%, 19%, 41%, and 51% photochromic behavior, respectively. Hence, extreme care must be taken when using the latter four RFP variants as acceptors in FRET studies, since a photochromic effect is easily confused with a changed FRET state, especially if one considers that the typical FRET contrast in many sensors is in the range of only 5–20%. The photochromic behavior can also interfere with characterization of FPs, like determination of photostability (Supplementary Fig. 8) or brightness (Supplementary Fig. 5l).