Table 1.
Properties of CyOFP1 and other large-Stokes-shift orange-red fluorescent proteins
| CyOFP1 | mBeRFP | LSSmOrange | LSSmKate1 | LSSmKate2 | mKeima | |
|---|---|---|---|---|---|---|
| Excitation peak (nm) | 497, 523a | 446 | 437 | 463 | 460 | 440 |
| Emission peak (nm) | 589 | 611 | 572 | 624 | 605 | 620 |
| EC at peak (mM−1cm−1) | 40 | 65 | 52 | 31 | 26 | 13 |
| QY | 0.76 | 0.27 | 0.45 | 0.08 | 0.17 | 0.24 |
| Brightnessb | 31 | 18 | 19 | 2.5 | 4.4 | 3.2 |
| Lifetime (ns) | 3.6 | 2.0 | ND | ND | 1.4e | 1.8e |
| Photostability (s)c | 111 | ND | ND | ND | ND | ND |
| pKa | 5.5 | 5.6 | 5.7 | 3.2 | 2.7 | 6.5 |
| Maturation (min)d | 15 | 60 | 140 | 100 | 150 | 160e |
| Reference | this work | 4 | 47 | 39 | 39 | 48 |
EC, extinction coefficient; QY, quantum yield; ND, not determined.
a
Peaks at 497 and 523 nm differ in excitation efficiency by less than 0.3%.
b
Calculated as the product of EC at peak and QY.
c
Predicted time for fluorescence to photobleach by 50% under arc-lamp illumination from initial emission rate of 1000 photons per molecule per second. For EGFP, this time is 170 s.
d
Half-time to full maturation after exposure to normoxic conditions.
e
Values from ref. 4.