Fluorophore diffusion in BL6 murine myocytes
| Fluorophore (MW, kD) . | T (°C) . | HR (nm) . | Fmyo/pip . | Fbound . | DX (cm2/s) . | DX-free (cm2/s) . | DX-H2O (cm2/s) . | Fold reduction . |
|---|---|---|---|---|---|---|---|---|
| Bodipy-FL-ATP (0.88) | 24 | 0.85 | 0.67 | 0.50 | 0.4 × 10−7 | 0.57 × 10−7 | 4.5 × 10−6a | >70 |
| Carboxyfluorescein (0.38) | 24 | 0.65 | 0.48 | 0.31 | 1.2 × 10−7 | 1.7 × 10−7 | 4.8 × 10−6b | 28 |
| Carboxyfluorescein (0.38) | 34 | 0.65 | 0.52 | 0.36 | 3.2 × 10−7 | 5.0 × 10−7 | 4.8 × 10−6b | 10 |
| Sulforhodamine (0.56) | 24 | 0.74 | 5.0 | 0.93 | 0.3 × 10−7 | 4.3 × 10−7 | 4.0–4.4 × 10−6c | 10 |
| TRITC-dextran (4.4) | 24 | 1.44 | 0.74 | 0.55 | 0.4 × 10−7 | 0.78 × 10−7 | 1.5 × 10−6d | 19 |
| 0.5 kD PEG (0.83) | 24 | 0.84 | 0.38 | 0.12 | 1.1 × 10−7 | 1.2 × 10−7 | 3 × 10−6e | 25 |
| 2 kD PEG (2.3) | 24 | 1.16 | 0.42 | 0.21 | 0.5 × 10−7 | 1.3 × 10−7 | 6 × 10−7e | 46 |
| 2 kD PEG-NH3 (2.3) | 24 | 1.16 | 0.48 | 0.31 | 0.33 × 10−7 | 0.48 × 10−7 | --- | ---- |
| 10 kD PEG (10.3) | 24 | 1.90 | 0.69 | 0.52 | 0.9 × 10−7 | 3.1 × 10−7 | 2.5 × 10−7e | 8 |
| Fluorophore (MW, kD) . | T (°C) . | HR (nm) . | Fmyo/pip . | Fbound . | DX (cm2/s) . | DX-free (cm2/s) . | DX-H2O (cm2/s) . | Fold reduction . |
|---|---|---|---|---|---|---|---|---|
| Bodipy-FL-ATP (0.88) | 24 | 0.85 | 0.67 | 0.50 | 0.4 × 10−7 | 0.57 × 10−7 | 4.5 × 10−6a | >70 |
| Carboxyfluorescein (0.38) | 24 | 0.65 | 0.48 | 0.31 | 1.2 × 10−7 | 1.7 × 10−7 | 4.8 × 10−6b | 28 |
| Carboxyfluorescein (0.38) | 34 | 0.65 | 0.52 | 0.36 | 3.2 × 10−7 | 5.0 × 10−7 | 4.8 × 10−6b | 10 |
| Sulforhodamine (0.56) | 24 | 0.74 | 5.0 | 0.93 | 0.3 × 10−7 | 4.3 × 10−7 | 4.0–4.4 × 10−6c | 10 |
| TRITC-dextran (4.4) | 24 | 1.44 | 0.74 | 0.55 | 0.4 × 10−7 | 0.78 × 10−7 | 1.5 × 10−6d | 19 |
| 0.5 kD PEG (0.83) | 24 | 0.84 | 0.38 | 0.12 | 1.1 × 10−7 | 1.2 × 10−7 | 3 × 10−6e | 25 |
| 2 kD PEG (2.3) | 24 | 1.16 | 0.42 | 0.21 | 0.5 × 10−7 | 1.3 × 10−7 | 6 × 10−7e | 46 |
| 2 kD PEG-NH3 (2.3) | 24 | 1.16 | 0.48 | 0.31 | 0.33 × 10−7 | 0.48 × 10−7 | --- | ---- |
| 10 kD PEG (10.3) | 24 | 1.90 | 0.69 | 0.52 | 0.9 × 10−7 | 3.1 × 10−7 | 2.5 × 10−7e | 8 |
All values are a mean of four or more measurements. From left to right: Column 1: Fluorophore analyzed. Column 2: Temperature of observations. Column 3: Hydrodynamic radius. Column 4: Ratio of fluorescence of pipette solution to myoplasm in close proximity after >20 min (Fmyo/pip). Values for BSA and GFP were 0.07 and 0.15, respectively, indicating exclusion from myoplasm. Column 5: Estimated fractions of fluorophores bound by cytoplasm, assuming the free cytoplasmic space to be one-third of total myocyte volume (Lu et al., 2016). . Column 6: Estimated diffusion coefficients for total fluorophores. with λmyo = 0.012 cm. Column 7: Diffusion coefficients for unbound fluorophore, estimated as . Column 8: Estimated diffusion coefficients for given compounds in free water. Column 9: Estimated fold reduction of diffusion coefficients of unbound compounds in murine myocyte cytoplasm versus water (Dx-H2O/Dx-free).
Fig.5.
Kramer et al., 2007.
Gendron et al., 2008 describes diffusion coefficients for multiple rhodamine derivatives.
Gribbon and Hardingham, 1998.
Waggoner et al., 1995.