AAT Bioquest

Fura-8™, pentasodium salt

Fluorescence excitation spectra of Fura-8™ in the presence of 0 to 39 µM free Ca2+.
Fluorescence excitation spectra of Fura-8™ in the presence of 0 to 39 µM free Ca2+.
Fluorescence excitation spectra of Fura-8™ in the presence of 0 to 39 µM free Ca2+.
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)260
Molecular weight751.59
Spectral properties
Excitation (nm)354
Emission (nm)524
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)
Although Fura-2 has become the preferred excitation-ratioable calcium indicator of choice, it has certain limitations (e.g., lower sensitivity than single wavelength calcium indicators such as Fluo-8® and Cal-520®). To address these concerns, AAT Bioquest has devoted considerable efforts to the development of Fura™ 8, a high-affinity ratiometric calcium indicator with improved sensitivity and higher signal-to-noise ratios. The fluorescence emission of Fura™ 8 is red-shifted to a longer visible wavelength, facilitating the detection of Fura™ 8 by common filter sets. Fura™ 8, pentasodium salt is membrane-impermeant and is excited at 355 nm and 415 nm and emits at 530 nm.


Common stock solution preparation

Table 1. Volume of Water needed to reconstitute specific mass of Fura-8™, pentasodium salt 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 mM133.051 µL665.256 µL1.331 mL6.653 mL13.305 mL
5 mM26.61 µL133.051 µL266.103 µL1.331 mL2.661 mL
10 mM13.305 µL66.526 µL133.051 µL665.256 µL1.331 mL

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)354
Emission (nm)524

Product Family

NameExcitation (nm)Emission (nm)
Fura-8™, pentapotassium salt354524
Fura-2, pentasodium salt336505



View all 4 citations: Citation Explorer
Nifedipine stimulates proliferation and migration of different breast cancer cells by distinct pathways
Authors: Zhao, Tao and Guo, Dongqing and Gu, Yuchun and Ling, Yang
Journal: Molecular Medicine Reports (2017): 2259--2263
Inhibition of pyruvate kinase M2 by reactive oxygen species contributes to the development of pulmonary arterial hypertension
Authors: Guo, Dongqing and Gu, Junzhong and Jiang, Hui and Ahmed, Asif and Zhang, Zhiren and Gu, Yuchun
Journal: Journal of molecular and cellular cardiology (2016): 179--187
Nifedipine promotes the proliferation and migration of breast cancer cells
Authors: Guo, Dong-Qing and Zhang, Hao and Tan, Sheng-Jiang and Gu, Yu-Chun
Journal: PloS one (2014): e113649


View all 84 references: Citation Explorer
Measurement of [Ca2+] in cell suspensions using indo-1
Authors: Nelemans A., undefined
Journal: Methods Mol Biol (2006): 47
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
Ratiometric intracellular calcium imaging in the isolated beating rat heart using indo-1 fluorescence
Authors: Eerbeek O, Mik EG, Zuurbier CJ, van 't Loo M, Donkersloot C, Ince C.
Journal: J Appl Physiol (2004): 2042
Negative inotropic effects of angiotensin II, endothelin-1 and phenylephrine in indo-1 loaded adult mouse ventricular myocytes
Authors: Sakurai K, Norota I, Tanaka H, Kubota I, Tomoike H, Endo M.
Journal: Life Sci (2002): 1173
Usefulness of the analytic method of intracellular calcium and the problems--aequorin and indo-1 signal
Authors: Endoh M., undefined
Journal: Nippon Yakurigaku Zasshi (2000): 361
Comment on "Usefulness of intracellular calcium analysis and the problem--aequorin and indo-1 signal"
Authors: Imaizumi Y., undefined
Journal: Nippon Yakurigaku Zasshi (2000): 101
Concentrations of caffeine greater than 20 mM increase the indo-1 fluorescence ratio in a Ca(2+)-independent manner
Authors: McKemy DD, Welch W, Airey JA, Sutko JL.
Journal: Cell Calcium (2000): 117
Measurement of [Ca2+]i in cell suspensions using indo-1
Authors: Nelemans A., undefined
Journal: Methods Mol Biol (1999): 41
Alpha-stat calibration of indo-1 fluorescence and measurement of intracellular free calcium in rat ventricular cells at different temperatures
Authors: Wang SQ, Zhou ZQ.
Journal: Life Sci (1999): 871
Intracellular calcium signals measured with indo-1 in isolated skeletal muscle fibres from control and mdx mice
Authors: Collet C, Allard B, Tourneur Y, Jacquemond V.
Journal: J Physiol (1999): 417