Name: Fluo-4, Pentapotassium Salt
Brand: AAT Bioquest
SKU: 20555
Availability: InStock

Fluo-4, Pentapotassium Salt

Calcium measurement is critical for numerous biological investigations. Fluorescent probes that show spectral responses upon binding calcium have enabled researchers to investigate changes in intracellular free calcium concentrations by using fluorescence microscopy, flow cytometry, fluorescence spectroscopy and fluorescence microplate readers. Fluo-3 and Fluo-4 are most commonly used among the visible light-excitable calcium indicators. Fluo-4 is an analog of fluo-3 with the two chlorine substituents replaced by fluorines, which results in increased fluorescence excitation at 488 nm and consequently higher fluorescence signal levels. Cells may be physically loaded with the cell-impermeant salt forms of these indicators using patch pipette or microinjection. These indicators are useful for fluorescence and confocal microscopy, flow cytometry, and microplate screening applications.

Protocol

COA

Catalog	Size	Price	Quantity
20555	1 mg	Price
20556	10x50 ug	Price

Calculators

Common stock solution preparation

Table 1. Volume of Water needed to reconstitute specific mass of Fluo-4, Pentapotassium 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 mg	0.5 mg	1 mg	5 mg	10 mg
1 mM	107.866 µL	539.328 µL	1.079 mL	5.393 mL	10.787 mL
5 mM	21.573 µL	107.866 µL	215.731 µL	1.079 mL	2.157 mL
10 mM	10.787 µL	53.933 µL	107.866 µL	539.328 µL	1.079 mL

Molarity calculator

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

Mass (Calculate)		Molecular weight		Volume (Calculate)		Concentration (Calculate)		Moles
mg	÷	927.08 g/mol	=	mL	x	mM	=	mmol

Physical properties

Dissociation constant (K_d, nM)	345
Molecular weight	927.08
Solvent	Water

Spectral properties

Extinction coefficient (cm ^-1 M ^-1)	82000
Excitation (nm)	495
Emission (nm)	528
Quantum yield	0.16 ¹

Storage, safety and handling

H-phrase	H303, H313, H333
Hazard symbol	XN
Intended use	Research Use Only (RUO)
R-phrase	R20, R21, R22
Storage	Freeze (< -15 °C)
UNSPSC	12352200

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Page updated on October 13, 2025