Table 2.
Photo-switching properties of selected FPs for SR-imaging by SMLM.
| FPs | λex (nm) | λem (nm) | λon/off (nm) | ε (M−1cm−1) | QY | on/off contrast |
Duty Cycle |
Photons/ localization |
# Switching Cycles |
clustering | Ref. |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Dendra2 | 490/553 | 507/573 | 405/488 | 45,000/35,000 | 0.5/0.55 | 300 | 4×10−6 | 686 | 2.7 | - | 56,62,63,240 |
| Dreiklang | 511 | 529 | 340/412 | 83,000 | 0.41 | 75 | N.R. | 400-700 | >160 | N.R. | 61,237,241 |
| Dronpa | 503 | 518 | 405/488 | 95,000 | 0.85 | 20 | 8×10−4 | 262 | 60-70 | - | 25,63,236,242 |
| mEos2 | 506/573 | 519/584 | 405/573 | 56,000/46,000 | 0.84/0.66 | 200 | 3×10−6 | 1000 | 2.8 | + | 62,63,227,228 |
| mEos3.2 | 507/572 | 516/580 | 405/572 | 63,400/32,200 | 0.84/0.55 | N.R. | 3×10−6 | 1000 | 2.4 | - | 62,63,229 |
| mMaple | 489/566 | 505/583 | 380/566 | 15,000/30,000 | 0.74/0.56 | 400 | 2×10−6 | 1000 | 3.4 | + | 62,63,228 |
| mMaple3 | 489/566 | 506/583 | 405/561 | N.R. | N.R. | N.R. | 6×10−7 | 675 | 2.8 | - | 63 |
| PAmCherry1 | 564 | 595 | ~370 | 18,000 | 0.46 | 4000 | 8×10−6 | 725 | 1 | + | 62,63,223 |
| PAGFP | 504 | 517 | 405 | 17,400 | 0.79 | 200 | 1.3×10−3 | 313 | N.R. | - | 49,63 |
Note: λex (excitation wavelength); λem (emission wavelength); λon/off (wavelengths for switching the fluorescence on and off, respectively); ε (extinction coefficient); QY (fluorescence quantum yield); on/off contrast (ratio of intensity of the emissive form to the dark form); duty cycle (fraction of time spent in the on state); photons/localization (number of detected photons per localization event); # switching cycles (number of switching cycles); ‘N.R.’ indicates the parameter was not reported;‘+’ indicates clustering or aggregation was observed in the ClpP assay by Wang et al.63 (‘-’ indicates no clustering).