TABLE 1.
Dye properties, and model parameters characterizing the cellular cytoplasm in terms of a reasonable fit to the single-cell data (Fig. 5), for each dye
| Symbol (if assigned) | Definition of parameter | Value for Alexa 350 | Value for Alexa 488 | Value for Alexa 594 |
|---|---|---|---|---|
| Molecular weight (excl. Na+ counterion) | 326.31 | 547.50 | 735.81 | |
| Daq | Diffusivity in bulk water at 25°C | 5.7 × 10−4 mm2/s | 4.3 × 10−4 mm2/s | 3.7 × 10−4 mm2/s |
| a | Stokes-Einstein equivalent radius | 4.3 Å | 5.7 Å | 6.6 Å |
| Net charge | −1 | −2 | −2 | |
| Dcyt | Diffusivity in cytoplasm | 1.85 × 10−4 mm2/s | 3.8 × 10−4 mm2/s | 2.4 × 10−4 mm2/s |
 |
Dimensionless forward rate coefficient for binding to cytoplasm | 6.6 | 3.5 | 2.97 |
| kcyt | Dimensional forward rate coefficient for binding to cytoplasm | 1.22 × 10−3 s−1 | 1.33 × 10−3 s−1 | 7.12 × 10−4 s−1 |
 |
Equilibrium constant for binding to cytoplasm | 5.75 | 10 | 6.1 |
In the cases of Alexa 350 and Alexa 594, for which two experimental curves were measured and fitted, the model parameters listed represent average values derived as described in the text.