TABLE 2.
Diffusion coefficients at 25°C of fluorescent probes in water and biofilms and calculated tortuosity indices
| Probe | Dwa (μm2 s−1) | Dbf (μm2 s−1) | Dw/Dbf | Tortuosity index |
|---|---|---|---|---|
| 3K-Dex | 186 | 6.59 | 28 | 5.3 |
| 10K-Dex | 108 | 0.69 | 157 | 12.5 |
| 40K-Dex | 34 | 0.59 | 58 | 7.6 |
| 70K-Dex | 30 | 0.36 | 83 | 9.1 |
| 100K-Lg | 56 | 0.24 | 233 | 15.3 |
| 150K-lg | 38 | 0.17 | 224 | 15.0 |
| 240K-PE | 45 | 0.10 | 450 | 21.2 |
a
Data were from the following sources: TR-dextrans (35), 100K-Ig (9), 150K-Ig (40), and 240K-PE (29). These data, obtained at a given temperature, were converted to Dw values at 25°C by using the relationship Dw,25 = (Dw,x × T25 × ηx)/(Tx × η25), where T is the absolute temperature (kelvin scale) and η is the viscosity of water (14).