Calcium Flux Assays

Independent of your calcium signaling platform, we have a solution for your needs. Our products are available in various kit sizes to accommodate all screens, large and small. Learn more about these versatile products by following the links below in the calcium indicator selection guide.

Calcium indicatorApplication
Fluo-4 DirectFluo-4 Direct Calcium Assay offers a homogenous, add-and-read Fluo-4 formulation ideal for HTS applications. The assay contains a background-suppressing quencher which allows for a large assay window even in the presence of serum-containing media.
Fluo-3Fluo-3 is the first generation of the Fluo family of products. Fluo-3 imaging has revealed the spatial dynamics of many elementary processes in Ca2+ signaling. Since about 1996, Fluo-3 has also been extensively used in cell-based high-throughput screening assays for drug discovery.
Fluo-4 AMFluo-4 AM is the market-leading fluorescent calcium assay reagent that does not contain a background suppressing quencher dye. Fluo-4 AM, is an analog of fluo-3 with the two chlorine substituents replaced by fluorines. This fairly minor structural modification results in increased fluorescence excitation at 488 nm and consequently higher signal levels for confocal microscopy, flow cytometry, and microplate screening applications.
Fluo-4 NWFluo-4 NW provides the same advantages as Fluo-4 AM but is an improved formulation that includes PowerLoad and requires no washes after media removal.
Fura-2Fura-2 has become the dye of choice for ratio-imaging microscopy, in which it is more practical to change excitation wavelengths than emission wavelengths. Upon binding Ca2+, fura-2 exhibits an absorption shift of the excitation spectrum between 300 and 400 nm, while monitoring the emission at ~510 nm.
Indo-1Indo-1 is a preferred dye for flow cytometry, where it is more practical to use a single laser for excitation — usually the 351–364 nm spectral lines of the argon-ion laser — and monitor two emissions. The emission maximum of indo-1 shifts from ~475 nm in Ca2+-free medium to ~400 nm when the dye is saturated with Ca2+.

Fluorescent dye loading and retention reagents

PowerLoad ConcentratePowerLoad Concentrate, an optimized formulation of nonionic, Pluronic surfactant polyols is designed to aid the solubilization of water-insoluble dyes in physiological media to achieve maximum loading of dyes into cells.
Water-soluble ProbenecidWater soluble Probenecid is an advanced formulation of traditional probenecid that dissolves in water for more convenient preparation. For dye retention issues, the use of probenecid to suppress efflux of fluorescent dyes is a favorable method for reducing baseline fluorescence.
CoelenterazineCoelenterazine and coelenterazine derivatives complex with aequorin to offer luminescent calcium readout in cells which can eliminate common cellular fluorescence interference issues.

For Research Use Only. Not for use in diagnostic procedures.