What is the use of Indo-1 calcium indicator?
What is the use of Indo-1 calcium indicator?
Indo-1 is a ratiometric and sensitive indicator dye for measuring intracellular calcium. Since its introduction in 1985, indo-1 has been cited in thousands of papers that describe its applications in a wide variety of cells. These important Ca 2+ indicators, developed by Roger Tsien and collaborators,…
What’s the difference between Fura-2 and Indo-1?
Indo-1 is a popular calcium indicator similar to Fura-2. In contrast to Fura-2, Indo-1 has a dual emissions peak. The main emission peak in calcium-free solution is 475 nm while in the presence of calcium the emission is shifted to 400 nm. It is widely used in flow cytometry .
Is there a calcium indicator similar to Fura-2?
Indo-1 is a popular calcium indicator similar to Fura-2. In contrast to Fura-2, Indo-1 has a dual emissions peak. The main emission peak in calcium-free solution is 475 nm while in the presence of calcium the emission is shifted to 400 nm. It is widely used in flow cytometry.
How is Indo-1 excited in the UV light?
Indo-1 is excited in the UV, and fluoresces at different wavelengths depending on whether it is bound to calcium (~420nm) or free (~510nm). The ratio of these two wavelengths can indicate changes in intracellular calcium concentration. Indo-1, because of the ratiometric quality, is the dye of choice for most flow applications.
How is the emission ratio of Indo-1 used?
The ability to make ratio measurements with indo-1, and their derivatives is an important property of these probes. At low concentrations of the indicator, use of the 405/485 nm emission ratio for indo-1 allows accurate measurements of the intracellular Ca 2+ concentration.
How is Indo-1 used in flow cytometry?
Indo-1 is especially useful for flow cytometry where it is easier to change the emission filters with a single excitation source (often the ultraviolet lines of the argon-ion laser in flow cytometers), and is particularly suited for multicolor fluorescence applications.
How is the emission of Indo-1 different from Fura?
In contrast to fura indicators, which exhibit large changes in absorption on Ca 2+ binding, the emission of indo-1 shifts from about 475 nm without Ca 2+ to about 400 nm with Ca 2+ when excited at about 350 nm (Figure 1).