Fura-2に代わるカルシウム指示薬
Key Features of Fura-8™
• Fura-8™ responses to calcium the same way as Fura-2 does
• Red-shifted dual excitation wavelengths (354 nm/415 nm)
• Better excited at 405 nm for flow cytometric applications
• Compatible with common filter sets
• Higher signal/background ratio than that of Fura-2
Although Fura-2 has been widely used as the preferred excitation-ratioable calcium indicator, it has certain limitations, e.g., lower sensitivity compared to the single wavelength calcium dyes such as Fluo-8® and Cal-520™. AAT Bioquest has recently developed Fura-8™ to improve the calcium response of Fura-2. As demonstrated in Figures 1.1 and 1.2, Fura-8™ AM is more sensitive to calcium than Fura-2 AM. In addition, Fura-8™ has its emission shifted to longer wavelength (Em = 525 nm). Fura-8™ might be also used for the flow cytometric analysis of calcium in cells due to its excellent excitation at 405 nm that perfectly matches the violet laser line of flow cytometer.
Figure 1.1. Fluorescence excitation spectra of Fura-8™ in the presence of 0 to 39 μM free Ca2+.
Figure 1.2. ATP dose responses in CHO-K1 cells measured with Fura-2 AM (blue) and Fura-8™ AM (red) respectively. CHO-K1 cells were seeded overnight at 40,000 cells/100 μL/well in a Costar black wall/clear bottom 96-well plate. The cells were incubated with Fura-2 AM and Fura-8™ AM calcium assay dye-loading solution respectively for 1 hour at room temperature. ATP (50 μL/well) was added by FlexStation®.
| Cat.# | Product Name | Size | Zero Calcium | High Calcium | Kd (nM) | ||
| Ex (nm) | Em(nm) | Ex (nm) | Em (nm) | ||||
| 21055 | Fura-8™ AM | 1 mg | 386 | 532 | 354 | 524 | 260 |
| 21056 | Fura-8™ AM | 10x50 ug | 386 | 532 | 354 | 524 | 260 |
| 21057 | Fura-8™, potassium salt |
1 mg | 386 | 532 | 354 | 524 | 260 |
| 21058 | Fura-8™, sodium salt | 1 mg | 386 | 532 | 354 | 524 | 260 |