New High Calcium Indicators

The excitation and emission wavelengths, photostability, and quantum yields of Fluo- and Indo-derivatives are comparable to the related low concentration Ca²⁺-indicators Fura 2, Indo 1 and Fluo 3. Fluo- and Indo-based indicators specially modified for measuring high calcium concentrations exhibit reduced sequestration of intracellular calcium, reduced perturbation of calcium transients, ability to measure short-lived transients, and an absence of magnesium effects. Thio H and Thio OMe are low affinity Ca²⁺-indicators.

Benefits:

• Useful for the determination of Ca²⁺ in intracellular compartments or monitoring steep increases of Ca²⁺ concentration
• Strong molar absorption and high quantum yield make Thio H three times brighter than Mag-Fura-2
• Strong fluorescence enables the use of low indicator concentrations and limits the buffering effects of the indicator
• Enables both types of ratiometric measurement
• Non-polar AM esters available