Invitrogen™ Rhod-2, Tripotassium Salt, cell impermeant

Labeled calcium indicators are molecules that exhibit an increase in fluorescence upon binding Ca²⁺. They have uses in many calcium signaling investigations, including measuring Ca²⁺ in cells and tissues that have high levels of autofluorescence and also for detecting Ca²⁺ release generated by photoreceptors and photoactivatable chelators.

• Fluorescence signal from these cells is generally measured using fluorescence microscopy
• Fluorescence intensity increase upon binding Ca²⁺: >100 fold
• K_d for Ca²⁺ in absence of Mg²⁺, in buffer: approximately 320μM
• Exhibit fluorescence increase upon binding Ca²⁺ with little shift in wavelength
• In addition, BAPTA-based indicators such as these bind various heavy metal cations (e.g., Mn²⁺, Zn²⁺, Pb²⁺) with substantially higher affinity than Ca²⁺
• Perturbations to calcium measurements caused by presence of these ions can be controlled using heavy metal-selective chelator TPEN

Calcium Detection, Cell Analysis, Cell Viability, Proliferation and Function, Ionic Homeostasis and Signaling