Table 2.
List of FPs mentioned in this review.
| FPs | λex a | λem b | ε c | φ d | BR e | pKa f | Photo-Stability g (min) | Lifetime (ns) | Maturation h (min) | Quaternary Structure | Reference |
|---|---|---|---|---|---|---|---|---|---|---|---|
| CFP and YFPs | |||||||||||
| Aquamarine | 430 | 474 | 26 | 0.89 | 23 | 3.3 | 79 | 4.1 | 2 times slower than ECFP i | weak dimer j | [35] |
| ECFP | 433 | 475 | 33 | 0.4 | 13 | 4.7 | 64 | 2.3, 3.0 k | ND | weak dimer j | [40,54] |
| mTurquoise2 | 434 | 474 | 30 | 0.93 | 28 | 3.1 | >64 | 3.8, 4.0 k | ND | monomer | [34] |
| mCerulean3 | 433 | 475 | 40 | 0.8 | 32 | 4.7 | ~35 | 3.7, 3.8 k | Kfold = 1.90 l | monomer | [34,37] |
| LUMP m | 420 | 470 | 24 | 0.55 | 13 | ND | ND | 13.6 | ND | monomer | [11] |
| mTFP1 | 462 | 492 | 64 | 0.85 | 54 | 4.3 | 110 | 3.2 | ND | monomer | [36] |
| EYFP | 513 | 527 | 83 | 0.61 | 51 | 6.9 | 60 | 2.9 | Kfold = 0.39 l | weak dimer j | [40,55] |
| mVenus | 515 | 528 | 92 | 0.57 | 53 | 6 | 15 | 3 | Kfold = 5.62 l | monomer | [55,56] [55,56,57] |
| sEYFP | 515 | 528 | 101 | 0.56 | 57 | 6.9 | ND | ND | ND | weak dimer j | [32] |
| mCitrine | 516 | 529 | 77 | 0.76 | 59 | 5.7 | 49 | 3.61 | ND | monomer | [40,58] |
| YPet | 517 | 530 | 104 | 0.77 | 80 | 5.6 | 49 | ND | ND | dimer | [40] |
| GFPs and RFPs | |||||||||||
| EGFP | 488 | 507 | 56 | 0.6 | 34 | 6 | 174 | 2.4 | 25 | weak dimer j | [40] |
| NowGFP | 494 | 502 | 57 | 0.76 | 43 | 6.2 | ND | 5.1 | ND | monomer | [43] |
| Clover | 505 | 515 | 111 | 0.76 | 84 | 6.1 | 50 | 3 | 30 | weak dimer | [2,46] |
| mClover3 | 506 | 518 | 109 | 0.78 | 85 | 6.5 | 80 | ND | ND | weak dimer | [45] |
| mNeonGreen | 506 | 517 | 116 | 0.8 | 93 | 5.7 | 158 | 3 | 10 | monomer | [46] |
| mRuby2 | 559 | 600 | 113 | 0.38 | 43 | 5.3 | 123 | ND | 150 | monomer | [2] |
| mRuby3 | 558 | 592 | 128 | 0.45 | 58 | 4.8 | 349 | ND | <150 | monomer | [45] |
| mCherry | 587 | 610 | 72 | 0.22 | 16 | 4.5 | 96 | 1.46 | 40 | monomer | [40,59] |
| FFPs and IFPs | |||||||||||
| mPlum | 590 | 649 | 41 | 0.1 | 4 | 4.5 | 53 | ND | 100 | monomer | [40,50] |
| eqFP650 | 592 | 650 | 65 | 0.24 | 16 | 5.7 | 30 n | ND | ND | dimer | [60] |
| mCardinal | 604 | 659 | 87 | 0.19 | 17 | 5.3 | 730 | ND | 27 | weak dimer | [47] |
| IFP1.4 m | 684 | 708 | 92 | 0.07 | 6 | 4.6 | ND | ND | 114 | dimer | [48] |
| iRFP m | 690 | 713 | 105 | 0.06 | 6 | 4 | ND | ND | 168 | dimer | [48] |
| LSS FPs and FP acceptors | |||||||||||
| mAmetrine | 406 | 526 | 45 | 0.58 | 26 | 6 | 2.8 | ND | 48 | monomer | [61,62] |
| LSS-mOrange | 437 | 572 | 52 | 0.45 | 23 | 5.7 | ~2.8 | ND | 138 | monomer | [62] |
| tdTomato | 554 | 581 | 138 | 0.69 | 95 | 4.7 | 98 | 3.1 | 60 | pseudo monomer | [40,63] |
| mKate2 | 588 | 633 | 63 | 0.4 | 25 | 5.4 | 81 | ND | 38 | weak dimer | [47] |
| Dark FPs | |||||||||||
| ShadowG | 486 | 510 | 89 | 0.005 | 0 | ND | ND | ND | 76 | monomer | [64] |
| REACh1 | 495 | 530 | ND | ND | NA | ND | ND | ND | ND | weak dimer | [65] |
| REACh2 | 510 | 538 | ND | ND | NA | ND | ND | ND | ND | weak dimer j | [65] |
| sREACh | 517 | 531 | 115 | 0.07 | 8 | ND | ND | ND | 133 | weak dimer j | [64] |
| Phototransformable FPs | |||||||||||
| rsTagRFP | 440 | 585 | 5 o | 0.005 o | ~0 o | 6.6 | ND | ND | 43 | weak dimer | [66] |
| 15 p | 0.001 p | ~0 p | |||||||||
| 567 | 585 | 37 o | 0.11 o | 4 o | |||||||
| 2 p | 0.11 p | 0.2 p | |||||||||
| PA-GFP | 504 | 517 | 17 | 0.79 | 14 | ND | ND | ND | ND | weak dimer j | [67] |
| Phanta | 506 | 516 | 98 | 0.003 | 0 | 4.5 | ND | ND | ND | monomer | [68] |
| FPs for Multicolor FRET | |||||||||||
| T-Sapphire | 399 | 511 | 44 | 0.6 | 26 | 4.9 | 25 | ND | 78 | weak dimer | [40,69] |
| mTagBFP | 402 | 457 | 52 | 0.63 | 33 | 2.7 | ND | 2.6 | ND | monomer | [70] |
| sfGFP | 485 | 510 | 83 | 0.65 | 54 | 5.5 | 157 | ND | ND | weak dimer j | [46] |
| CyOFP1 | 497 | 589 | 40 | 0.76 | 30.4 | 5.5 | 111 | 3.6 | 15 | weak dimer | [71] |
| mOrange2 | 549 | 565 | 58 | 0.6 | 35 | 6.5 | 228 | ND | 270 | monomer | [63] |
| mKOκ | 551 | 563 | 105 | 0.61 | 64 | 4.2 | ND | ND | ND | monomer | [42] |
| TagRFP | 555 | 584 | 100 | 0.48 | 49 | 3.8 | 37 | 2.3 | 100 | weak dimer | [63,72] |
| DsRed | 556 | 586 | 57 | 0.79 | 45 | 16 | ~678 | 3.65 | ~600 | tetramer | [58,73,74] |
a Excitation maximum in nm; b Emission maximum in nm; c Peak extinction coefficient in mM−1·cm−1; d Quantum yield; e Brightness; product of ε and φ; f pH at which the fluorescence intensity is 50% of its maximum value; g The time to photobleach from 1000 down to 500 emitted photons per second; h The time for fluorescence to obtain half-maximal value after exposure to oxygen; i Maturation of Aquamarine is based on comparison of ECFP and Aquamarine and is its better photostability is likely due to increased rigidity; j Can be made monomeric with A206K mutation; k Phase/modulation lifetime; l Refolding rate from denatured protein in 10−2/s; m Non-autofluorescent FPs. Biliverdin IXα (BV) and 6,7-dimethyl-8-(1′-dimethyl-ribityl) lumazine are the chromphores for NIR FPs and LUMP, respectively. n Photostability of eqFP650 is based on a comparison of photostability between eqFP650 and mCherry; o ON state of rsTagRFP; p OFF state of rsTagRFP.