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Fura-2, AM Ester

Fura-2, AM ester is a ratiometric calcium indicator that is membrane-permeant and can thus be loaded into cells via incubation.

Product Attributes


Calcium indicators

Cell permeability

Membrane permeant

Indicator type


CAS number



363/512 nm (no Ca2+); 335/505 nm (high Ca2+) (after hydrolysis)

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10 x 100 ug
1 mg
20 x 50 ug
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Product Description

Fura-2, AM ester is a ratiometric fluorescent dye that binds to free intracellular calcium, and is the preferred dye for ratiometric imaging microscopy. Fura-2, AM ester is membrane-permeant and thus can be loaded into cells via incubation. Because of the relatively low water solubility of the AM ester, the mild detergent Pluronic F-127 (catalog no. 59004) is often used as a dispersing agent to facilitate cell loading. Fura-2, AM ester itself does not bind Ca2+, but it is readily hydrolyzed to Fura-2 by endogenous esterases once it enters cells.

Fura-2 fluorescence can be detected using flow cytometry, fluorescence microscopy, or certain fluoresence microplate readers. Upon calcium binding, the fluorescent excitation maximum of the indicator undergoes a blue shift from 363 nm (Ca2+-free) to 335 nm (Ca2+-saturated), while the fluorescence emission maximum is relatively unchanged at ~510 nm. A major use of Fura-2 is in drug discovery, for measuring intracellular calcium mobilization after activation of G protein-coupled receptors (GPCRs) and calcium channels.

  • Light yellow solid soluble in DMSO
  • Store at -20°C and protect from light, especially in solution
  • Kd: 145 nM (22°C in pH 7.2 buffer) (after hydrolysis)
  • λExEm (no Ca2+) = 363/512 nm; λExEm (high Ca2+) = 335/505 nm (after hydrolysis)
  • ε (363 nm, no Ca2+) = 27,000 M-1cm-1; ε (335 nm, high Ca2+) = 35,000 M-1cm-1 (after hydrolysis)
  • C44H47N3O24
  • MW: 1001.9
  • [108964-32-5]



Fura-2 Products


Unit Size

Catalog Number

Fura-2, pentaammonium salt1 mg50030
Fura-2, pentapotassium salt1 mg50031
Fura-2, pentasodium salt1 mg50032
Fura-2, AM ester10 x 100 ug50033
20 x 50 ug50033-1
1 mg50034
Fura-2, AM ester, 1 mM solution1 mL50029


1. Am J Physiol 263, 1292 (1992).

2. J Mol Cell Cardiol 24, 937 (1992).


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