Calcium Flux Dyes Chart
| Dye | Excitation | Emission | Function | Benefits | Limitations |
|---|---|---|---|---|---|
| eFluor® 514 Calcium Sensor Dye | 490 nm | 514 nm | Fluorescence intensity increases upon binding free Ca2+ |
Allows qualitative/semi-quantitative measurements of intracellular free Ca2+. Compatible with flow cytometry, fluorescence microscopy, microplate readers, and spectrophotometry. Better cellular uptake and brighter than Fluo-3 or Fluo-4. |
Only semi-quantitatve. |
| Indo-1 AM | 346 nm | 410 nm (bound) 485 nm (unbound) |
Peak emission decreases upon binding free Ca2+ |
Allows quantitative measurement of free Ca2+. Compatible with flow cytometry, fluorescence microscopy, microplate readers, and spectrophotometry. Ratiometric measurements possible. |
Compensation between bound/ unbound emission may be difficult. Not compatible with eFluor® 450, 605NC, 625NC, 650 NC, or other violet laser-excitable dyes. |
| Fura-2 AM | 300 nm (bound) 400 nm (unbound) |
510 nm | Peak excitation decreases upon binding free Ca2+ |
Ideal for measuring low to medium concentrations of Ca2+ by spectrophotometry or microscopy (when specific excitiation wavelengths can be used). Compatible with ratiometric imaging microscopy. |
Not for use with flow cytometry. Kd is highly sensitive to changes in pH, temperature, ionic strength and viscosity of the cytosol. |
