Table 3. Optical Properties of Representative FPs.
| Protein | λexa(nm) | λemb(nm) | εabsc(M–1 cm–1) | Φfd(%) | pKa | Relative Brightnesse(% of EGFP) | refs |
|---|---|---|---|---|---|---|---|
| Sirius | 355 | 424 | 15,000 | 24 | <3.0 | 11 | (183) |
| EBFP2 | 383 | 448 | 32,000 | 56 | 4.5 | 53 | (184, 185) |
| TagBFP | 402 | 457 | 52,000 | 63 | 2.7 | 98 | (185) |
| mTurquoise | 434 | 474 | 30,000 | 84 | 4.5 | 75 | (186) |
| ECFP | 434 | 475 | 32,500 | 41 | 4.7 | 40 | (187) |
| TagCFP | 458 | 480 | 37,000 | 57 | 4.7 | 63 | (188) |
| mTFP1 | 462 | 492 | 64,000 | 85 | 4.3 | 162 | (187) |
| EGFP | 488 | 507 | 56,000 | 60 | 6.0 | 100 | (187) |
| mWasabi | 493 | 509 | 70,000 | 80 | 6.5 | 167 | (189) |
| mNeonGreen | 506 | 517 | 116,000 | 80 | 5.7 | 276 | (190) |
| EYFP | 514 | 527 | 84,000 | 61 | 6.5 | 153 | (191) |
| Citrine | 516 | 529 | 77,000 | 76 | 5.7 | 174 | (192) |
| mOrange | 548 | 562 | 71,000 | 69 | 6.5 | 146 | (178) |
| mKO2 | 551 | 565 | 63,800 | 57 | 5.5 | 108 | (193) |
| TagRFP | 555 | 584 | 100,000 | 48 | <4.0 | 143 | (194) |
| mRuby2 | 559 | 600 | 113,000 | 38 | 5.3 | 128 | (195) |
| mCherry | 587 | 610 | 72,000 | 22 | <4.5 | 47 | (178) |
| mKate2 | 588 | 633 | 62,500 | 40 | 5.4 | 74 | (196) |
| mNeptune | 600 | 650 | 67,000 | 20 | 5.4 | 40 | (197) |
| iRFP670 | 643 | 670 | 114,000 | 11 | 4.0 | 38 | (181) |
| TagRFP675 | 598 | 675 | 46,000 | 8 | 5.7 | 11 | (198) |
| iRFP702 | 673 | 702 | 93,000 | 8 | 4.5 | 23 | (181) |
| iRFP713 | 690 | 713 | 98,000 | 6 | 4.5 | 18 | (181) |
| iRFP720 | 702 | 720 | 96,000 | 6 | 4.5 | 17 | (181) |
| pH-sensitive FPs | |||||||
| Ecliptic pHluorin | 495 | 511 | NDf | ND | 7.1 | ND | (199) |
| Super-Ecliptic pHluorin | 495 | 512 | ND | ND | 7.2 | ND | (200) |
| pHuji | 566 | 598 | 31,000 | 22 | 7.7 | 20 | (200) |
| pHoran4 | 547 | 561 | 83,000 | 66 | 7.5 | 163 | (200) |
a
Maximum excitation wavelength.
b
Maximum emission wavelength.
c
Extinction coefficient.
d
Fluorescence quantum yield.
e
The relative brightness values were calculated from the product of the molar extinction coefficient and quantum yield, divided by the value for EGFP.
f
Not determined.