Table 1.
Summary of results of FCS studies on five red FPs and mCerulean3.
| Flickering threshold (kW/cm2) | Optimal power (kW/cm2) | D in soln (μm2/s) | D in live cells (μm2/s) | D FP-BZip in cytosol (μm2/s) | D FP-BZip in nucleus (μm2/s) | Brightness published (a.u.) [ref] | Mb (FPs in live cells) | Mb (FP-BZip live cells) | |
|---|---|---|---|---|---|---|---|---|---|
| mCherry | 0.39 | 0.11 | 96.6 ± 8.1 | 30.0 ± 3.1 | 21.1 ± 8.5 | 8.6 ± 2.2 | 2.62 [6] | 2.0 ± 0.2 | 1.65 |
| mApple | -- | 0.075 | 122.2 ± 7.5 | 37.8 ± 8.5 | 27.4 ± 7.3 | 14.2 ± 4.0 | 6.06 [11] | 5.6 ± 1.6a | n.d. |
| TagRFP-T | 0.91 | 0.10–0.13 | 89.9 ± 8.0 | 26.6 ± 3.9 | 23.9 ± 4.6 | 7.9 ± 1.8 | 8.02 [13] | 13.4 ± 2.5 | 9.8 ± 1.9 |
| mRuby2 | 0.41 | 0.17 | 96.2 ± 5.6 | 19.1 ± 3.6 | 24.6 ± 4.4 | 9.7 ± 2.7 | 7.04 [9] | 6.8 ± 1.6 | 7.0 ± 0.9 |
| FusionRed | 0.11 | 0.11 | 93.0 ± 13.7 | 33.2 ± 6.8 | n.d. | n.d. | 2.95 [8] | 2.7 ± 0.6 | n.d. |
| mCerulean3 | n.d. | n.d. | 92.5 ± 8.5 | 29.3 ± 4.4 | 22.6 ± 5.8 | 7.3 ± 2.6 | n.d. | n.d. | n.d. |
a
Autocorrelation fitting for mApple did not provide an accurate value for D using a one-component fit; Therefore, data were fit using a diffusion model in which N was determined by including a flickering component and setting D equal to DmCherry (see Section 3.2 and Equation (4)).