AAT Bioquest

Fura Red, AM *CAS 149732-62-7*

Product Image
Product Image
Gallery Image 1
Ordering information
Catalog Number
Unit Size
Add to cart
Additional ordering information
InternationalSee distributors
Bulk requestInquire
Custom sizeInquire
ShippingStandard overnight for United States, inquire for international
Request quotation
Physical properties
Dissociation constant (Kd, nM)400
Molecular weight1088.99
Spectral properties
Excitation (nm)435
Emission (nm)639
Storage, safety and handling
H-phraseH303, H313, H333
Hazard symbolXN
Intended useResearch Use Only (RUO)
R-phraseR20, R21, R22
StorageFreeze (< -15 °C); Minimize light exposure


Molecular weight
Dissociation constant (Kd, nM)
Excitation (nm)
Emission (nm)
Fura Red is a visible light-excitable fura-2 analog that offers unique possibilities for ratiometric measurement of calcium ion in single cells by microphotometry, imaging or flow cytometry when used with single excitation, green-fluorescent calcium indicators. Fura Red AM is the cell-permeable version of Fura Red used for noninvasive intracellular loading. Fura Red AM can be simultaneously loaded into cells with Fluo-3 AM, Fluo-8 AM or Cal-520 AM. An advantage of combining two calcium dyes is that dyes with longer excitation wavelengths can be used. This usually causes less harm to the cells than using ratiometric dyes that are excited with UV- or near UV-light (e.g. Fura-2), as light at visible wavelengths is less phototoxic.


Fluorescence microplate reader

Excitation435, 470
Emission630, 650
CutoffEx/Em = 435/630, cutoff 610. Ex/Em = 470/650, cut off 630
Recommended plateBlack wall/clear bottom
Instrument specification(s)Bottom read mode/Programmable liquid handling

Example protocol


Unless otherwise noted, all unused stock solutions should be divided into single-use aliquots and stored at -20 °C after preparation. Avoid repeated freeze-thaw cycles

Fura Red AM Stock Solution
  1. Prepare a 2 to 5 mM stock solution of Fura Red AM in high-quality, anhydrous DMSO.


Fura Red AM Working Solution
  1. On the day of the experiment, either dissolve Fura Red AM in DMSO or thaw an aliquot of the indicator stock solution to room temperature.

  2. Prepare a 2 to 20 µM Fura Red AM working solution in a buffer of your choice (e.g., Hanks and Hepes buffer) with 0.04% Pluronic® F-127. For most cell lines, Fura Red AM at a final concentration of 4-5 μM is recommended. The exact concentration of indicators required for cell loading must be determined empirically.

    Note: The nonionic detergent Pluronic® F-127 is sometimes used to increase the aqueous solubility of Fura Red AM. A variety of Pluronic® F-127 solutions can be purchased from AAT Bioquest.

    Note: If your cells contain organic anion-transporters, probenecid (1-2 mM) may be added to the dye working solution (final in well concentration will be 0.5-1 mM) to reduce leakage of the de-esterified indicators. A variety of ReadiUse™ Probenecid products, including water-soluble, sodium salt, and stabilized solutions, can be purchased from AAT Bioquest.


Following is our recommended protocol for loading AM esters into live cells. This protocol only provides a guideline and should be modified according to your specific needs.

  1. Prepare cells in growth medium overnight.
  2. On the next day, add 1X Fura Red AM working solution to your cell plate.

    Note: If your compound(s) interfere with the serum, replace the growth medium with fresh HHBS buffer before dye-loading.

  3. Incubate the dye-loaded plate in a cell incubator at 37 °C for 30 to 60 minutes.

    Note: Incubating the dye for longer than 1 hour can improve signal intensities in certain cell lines.

  4. Replace the dye working solution with HHBS or buffer of your choice (containing an anion transporter inhibitor, such as 1 mM probenecid, if applicable) to remove any excess probes.
  5. Add the stimulant as desired and simultaneously monitor fluorescence intensity using a fluorescence plate reader, which contains a programmable liquid handling system such as a FlexStation, at Ex/Em1 = 435/630 nm cutoff 610 nm and Ex/Em2 = 470/650 nm cutoff 630 nm.


Common stock solution preparation

Table 1. Volume of DMSO needed to reconstitute specific mass of Fura Red, AM *CAS 149732-62-7* to given concentration. Note that volume is only for preparing stock solution. Refer to sample experimental protocol for appropriate experimental/physiological buffers.

0.1 mg0.5 mg1 mg5 mg10 mg
1 mM91.828 µL459.141 µL918.282 µL4.591 mL9.183 mL
5 mM18.366 µL91.828 µL183.656 µL918.282 µL1.837 mL
10 mM9.183 µL45.914 µL91.828 µL459.141 µL918.282 µL

Molarity calculator

Enter any two values (mass, volume, concentration) to calculate the third.

Mass (Calculate)Molecular weightVolume (Calculate)Concentration (Calculate)Moles


Open in Advanced Spectrum Viewer

Spectral properties

Excitation (nm)435
Emission (nm)639



View all 7 citations: Citation Explorer
P-selectin-dependent leukocyte adhesion is governed by endolysosomal two-pore channel 2
Authors: Goretzko, Jonas and Pauels, Inga and Heitzig, Nicole and Thomas, Katharina and Kardell, Marina and Na{\ss}, Johannes and Krogsaeter, Einar Kleinhans and Schloer, Sebastian and Spix, Barbara and Matos, Anna L{\'\i}via Linard and others,
Journal: Cell Reports (2023): 113501
Acute and long-term effects of cannabinoids on hypertension and kidney injury
Authors: Golosova, Daria and Levchenko, Vladislav and Kravtsova, Olha and Palygin, Oleg and Staruschenko, Alexander
Journal: Scientific reports (2022): 1--12
Arachidonic acid-regulated calcium signaling in T cells from patients with rheumatoid arthritis promotes synovial inflammation
Authors: Ye, Zhongde and Shen, Yi and Jin, Ke and Qiu, Jingtao and Hu, Bin and Jadhav, Rohit R and Sheth, Khushboo and Weyand, Cornelia M and Goronzy, J{\"o}rg J
Journal: Nature communications (2021): 1--17
TRPA1 channels are a source of calcium-driven cardiac mechano-arrhythmogenicity
Authors: Cameron, Breanne A and Stoyek, Matthew R and Bak, Jessi J and Quinn, T Alexander
Journal: bioRxiv (2020)
Role of opioid signaling in kidney damage during the development of salt-induced hypertension
Authors: Golosova, Daria and Palygin, Oleg and Bohovyk, Ruslan and Klemens, Christine A and Levchenko, Vladislav and Spires, Denisha R and Isaeva, Elena and El-Meanawy, Ashraf and Staruschenko, Alexander
Journal: Life science alliance (2020)
In vitro characterization of rare anti-$\alpha$IIb$\beta$3 isoantibodies produced by Glanzmann thrombasthenia patients that severely block fibrinogen binding and generate procoagulant platelets via complement activation
Authors: Lee, Christine SM and Huguenin, Yoann and Pillois, Xavier and Moulieras, Mikeldi and Marcy, Ella and Whittaker, Shane and Chen, Vivien MY and Fiore, Mathieu
Journal: Research and Practice in Thrombosis and Haemostasis


View all 12 references: Citation Explorer
Ratiometric analysis of fura red by flow cytometry: a technique for monitoring intracellular calcium flux in primary cell subsets
Authors: Wendt ER, Ferry H, Greaves DR, Keshav S.
Journal: PLoS One (2015): e0119532
A flow cytometric comparison of Indo-1 to fluo-3 and Fura Red excited with low power lasers for detecting Ca(2+) flux
Authors: Bailey S, Macardle PJ.
Journal: J Immunol Methods (2006): 220
Use of co-loaded Fluo-3 and Fura Red fluorescent indicators for studying the cytosolic Ca(2+)concentrations distribution in living plant tissue
Authors: Walczysko P, Wagner E, Albrechtova JT.
Journal: Cell Calcium (2000): 23
Monitoring calcium in outer hair cells with confocal microscopy and fluorescence ratios of fluo-3 and fura-red
Authors: Su ZL, Li N, Sun YR, Yang J, Wang IM, Jiang SC.
Journal: Shi Yan Sheng Wu Xue Bao (1998): 323
Problems associated with using Fura-2 to measure free intracellular calcium concentrations in human red blood cells
Authors: Blackwood AM, Sagnella GA, Mark and u ND, MacGregor GA.
Journal: J Hum Hypertens (1997): 601
Calcium transient alternans in blood-perfused ischemic hearts: observations with fluorescent indicator fura red
Authors: Wu Y, Clusin WT.
Journal: Am J Physiol (1997): H2161
IgG-induced Ca2+ oscillations in differentiated U937 cells; a study using laser scanning confocal microscopy and co-loaded fluo-3 and fura-red fluorescent probes
Authors: Floto RA, Mahaut-Smith MP, Somasundaram B, Allen JM.
Journal: Cell Calcium (1995): 377
Localization of calcium entry through calcium channels in olfactory receptor neurones using a laser scanning microscope and the calcium indicator dyes Fluo-3 and Fura-Red
Authors: Schild D, Jung A, Schultens HA.
Journal: Cell Calcium (1994): 341
Improved sensitivity in flow cytometric intracellular ionized calcium measurement using fluo-3/Fura Red fluorescence ratios
Authors: Novak EJ, Rabinovitch PS.
Journal: Cytometry (1994): 135
The distribution of intracellular calcium chelator (fura-2) in a population of intact human red cells
Authors: Lew VL, Etzion Z, Bookchin RM, daCosta R, Vaananen H, Sassaroli M, Eisinger J.
Journal: Biochim Biophys Acta (1993): 152