Table 1.
Spectroscopic properties of IrisFP in solution
| Parameter | Green IrisFP | Red IrisFP | Green EosFP | Red EosFP |
|---|---|---|---|---|
| λmax, ex/em, nm | 488 / 516 | 551 / 580 | 506 / 516 | 571 / 581 |
| ε, M−1 cm−1 | 52,200 | 35,400 | 72,000 | 41,000 |
| QYfluorescence | 0.43 ± 0.02 | 0.47 ± 0.02 | 0.70 ± 0.02 | 0.62 ± 0.03 |
| QYoff switching* | 0.014 | 0.0020 | — | — |
| QYon switching* | 0.5 | 0.047 | — | — |
| QYgreen-to-red conversion | 0.0018 | — | 0.0008 | — |
| Effoff† | ≈0.85 | ≈0.75 | — | — |
| t1/2, thermal recovery, h | 5.5 | 3.2 | — | — |
Detailed experimental procedures are described in SI Text. λmax, peak wavelength; ex, excitation; em, emission; ε, extinction coefficient; QY, quantum yield; t1/2, half-life.
*Standard deviations are estimated as 25%.
†Switching efficiencies based on the following illumination conditions: Green IrisFP: 473 nm, 40 mW, ≈10 min. Red IrisFP: 532 nm, 50 mW, ≈10 min.