FCS Classroom
Rhodamine 6G Viscosity Titration
Rhodamine 6G was measured on the QuantumXpert FCS spectrometer at several viscosities to determine the linearity of correlation time dependence on viscosity.
The plot of τD vs. viscosity, below, shows that the relationship between τD and viscosity is linear over the entire experimental range (1.15 - 20 cP).
Table of Viscosity and Correlation Time (τD)
| Viscosity (cP) | τD | Std Error (N) |
|---|---|---|
| 1.15 | 0.00155 | 5.26x10-5 (10) |
| 2.00 | 0.00276 | 1.73x10-4 (10) |
| 2.65 | 0.00400 | 1.66x10-4 (10) |
| 3.70 | 0.00642 | 4.97x10-4 (9) |
| 4.80 | 0.00672 | 3.49x10-4 (8) |
| 5.65 | 0.00863 | 3.29x10-4 (10) |
| 7.65 | 0.0114 | 8.71x10-4 (10) |
| 9.85 | 0.0127 | 8.74x10-4 (6) |
| 13.7 | 0.0223 | 0.00192 (5) |
| 20.0 | 0.0281 | 0.0015 (10) |
Plot of Correlation Time (τD) vs. Viscosity
For complete details of this experiment, please see the assay example, Using Viscosity to Simulate Changes in Molecular Size.