Table I.
E-cadherin/GFP Diffusion Coefficient Measurements
| Radius | D × 10−10 | SD | n | |||
|---|---|---|---|---|---|---|
| μm | cm2/s | |||||
| 4.1 | 4.14 | 1.4 | 7 | |||
| 2.4 | 3.6 | 1.4 | 10 | |||
| 1.7 | 3.3 | 1.7 | 11 | |||
| all data | 3.6 | 1.5 | 26 |
Data are summarized from photobleaching EcadGFP in membrane lamella not involved in cell–cell adhesion using different-sized photobleach areas. Typically, circular spots of a 120-pixel radius were generated with a 380 × 240 pixel scan raster, and the spot radius (1.7–4.1 μm) at the specimen was varied by adjusting pixel sizes within the range of 0.01–0.05 μm. The photobleaching recovery part of the data was inported into Igor Pro, and the diffusion coefficient (D) was calculated according to the equation D = 0.224
r2/to, where r is the radius of the bleached region. These experiments show that EcadGFP diffusion time was related to the square of the photobleach radius as expected from simple diffusion theory.