What is the emission spectrum of Indo-1?
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Emission Spectrum of Indo-1
Indo-1 is a popular calcium indicator used in fluorescence microscopy and flow cytometry. It is a ratiometric dye, meaning it can emit light at two different wavelengths depending on the calcium concentration in its environment. This property makes Indo-1 particularly useful for measuring calcium ion (Ca2+) concentrations in cells and tissues.
Upon binding to calcium ions, the emission spectrum of Indo-1 shifts. In the absence of calcium, Indo-1 primarily emits at a wavelength of around 485 nm, producing a blue fluorescence. When calcium binds to Indo-1, the emission peak shifts to approximately 405 nm, resulting in a violet fluorescence. This shift in the emission spectrum allows researchers to determine the relative concentration of calcium ions by comparing the intensity of fluorescence at these two wavelengths.
Key Features of Indo-1's Emission Spectrum:
- Dual Emission Peaks: ~485 nm (blue) in calcium-free form and ~405 nm (violet) when bound to calcium.
- Ratiometric Measurement: Allows for the calculation of calcium concentrations based on the ratio of fluorescence intensities at the two emission peaks.
- High Sensitivity: Enables the detection of minute changes in calcium levels within cells.
Understanding the emission spectrum of Indo-1 is crucial for accurately interpreting calcium imaging experiments. The ability to measure calcium dynamics in real-time provides invaluable insights into cellular processes, signaling pathways, and the effects of pharmacological agents.