Table 1.
Summary of the 2PA properties of representative fluorescent proteins. Two-photon absorption cross section (σ2), two-photon brightness (σ2’), both per mature protein are presented in two spectral regions, corresponding to the short- and long-wavelength transitions.
Short-wavelength band | Long-wavelength band | |||||
---|---|---|---|---|---|---|
Protein | λ2PA (nm) | σ2 (GM) | σ2 × φ (GM) | λ2PA (nm) | σ2 (GM) | σ2 × φ (GM) |
EBFP2.041 | 552 | 16 | 11 | 750 | 13 | 9.2 |
ECFP (Clontech) | 550 | 15 | 7.8 | 857 | 23 | 12 |
Cerulean41 | 550 | 27 | 16 | 858 | 23 | 13 |
mTFP1.042 | 667 | 6.4 | 5.4 | 875 | 70 | 59 |
EGFP (Clontech) | 660 | 22 | 17 | 927 | 39 | 30 |
mAmetrine43 | 655 | 19 | 13 | 809 | 56 | 40 |
Citrine44 | 590 | 34 | 23 | 968 | 10 | 6.7 |
mKok45 | 686 | 93 | 67 | 1044 | 41 | 30 |
mOrange31 | 640 | 200 | 140 | 1080 | 67 | 47 |
TagRFP46 | 759 | 300 | 130 | 1050 | 95 | 42 |
tdTomato31 | 684 | 316 | 228 | 1050 | 278 | 200 |
DsRed247 | 700 | 112 | 79 | 1050 | 103 | 73 |
mCherry31 | 740 | 101 | 24 | 1080 | 27 | 6.4 |
mRaspberry48 | 704 | 346 | 65 | 1118 | 31 | 5.8 |
mPlum48 | 724 | 114 | 15 | 1105 | 22 | 2.9 |
tdKatushka249 | 710 | 645 | 285 | 1100 | 143 | 63 |
mKate249 | 712 | 216 | 91 | 1140 | 72 | 30 |
mNeptune50 | 750 | 335 | 57 | 1105 | 70 | 12 |
Note: To obtain σ2 and σ2’ per chromophore in the case of dimers, one has to take one-half of the corresponding values presented in the Table.