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Calcium Flux Dyes Chart

Calcium Flux Dyes
DyeExcitationEmissionFunctionBenefitsLimitations
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.