Calcium Ion Probe

BAPTA-AM is a calcium chelator that is cell-permeable and selective, blocking hERG, hKv1.3, and hKv1.5 channels (IC50=1.3 1.45 1.23 μM). BAPTA-AM has a 105-fold higher affinity for Ca2+ than for Mg2+, and can be used for the role of calcium in cell signaling.

Alizarin Complexone (Alizarin-3-methyliminodiacetic acid) is an inhibitor of Rous-associated virus 2 reverse transcriptase. Alizarin Complexone can be used as a calcium-tracer and a chelating agent for biological studies.

Fura-FF pentapotassium salt is a low affinity calcium fluorescent dye (Ex Em: 365 514 nm, no calcium; 339 507 nm, high calcium).

Fura-2 is a ratiometric fluorescent calcium indicator that can be used to detect calcium in cells. It is a pentacarboxylate that displays excitation maxima of 340 and 380 nm at high and low calcium concentrations, respectively, when the emission is fixed at 510 nm, enabling determination of ratiometric measurements of calcium influx in live cells.

BTC AM is a cell-permeable acetoxy-methyl ester of BTC . As BTC AM enters cells, it is hydrolyzed by intracellular esterases to produce BTC. BTC is a low affinity calcium indicator (Kd = 7-26 μM) that displays excitation emission spectra of 401 529 nm, respectively. It exhibits a shift in the excitation maximum from approximately 480 to 401 nm upon calcium binding, enabling determination of ratiometric calcium measurements. BTC is suitable for detecting elevated calcium levels associated with activation of smooth muscle, neurons, and intracellular calcium stores.

Quin-2AM is a fluorescent Ca2+ chelator with a high affinity for calcium.

Rhod-FF AM is a cell-permeant acetoxymethyl ester of the fluorescent calcium indicator rhod-FF . As rhod-FF AM enters cells, it is hydrolyzed by intracellular esterases to produce rhod-FF. Rhod-FF is a difluorinated analog of the cell-impermeant calcium indicator rhod-2. It has a very low affinity for calcium (Kd = 320 μM). Low affinity calcium indicators are particularly useful for studying compartments with high concentrations of calcium, such as endoplasmic reticulum, where high affinity dyes will be insensitive to luminal fluctuations. Rhod-FF has excitation emission maxima of approximately 552 and 580 nm, respectively.

Fluo-3 (ammonium salt) is a fluorescent calcium indicator commonly used in flow cytometry and cell-based experiments to detect changes in intracellular calcium levels. [1] Its absorption maximum at 506 nm makes it compatible with excitation at 488 nm by argon-ion laser sources. Fluo-3 provides intense fluorescence upon binding calcium, detected at a maximum emission at 526 nm which can be monitored by FL1 (green, 525 nm band pass) sensors in flow cytometry.

PAO-Nap is a chemically modified version of PAO, in which a naphthalimide fluorophore is attached to the compound using a linker called aminocaproic acid. This modified compound, PAO-Nap, exhibits a selective targeting of thioredoxin reductase, leading to the induction of apoptosis in HL-60 cells through oxidative stress mechanisms[1].

Coelenterazine hcp is a synthetic bioluminescent luciferin that displays an emission maximum of 445 nm.1It has been used as a calcium indicator and substrate to quantifyRenillaluciferase activity.1,2,3 1.Sabnis, R.W.Handbook of biological dyes and stains: Synthesis and industrial applications(2010) 2.Shimomura, O., Kishi, Y., and Inouye, S.The relative rate of aequorin regeneration from apoaequorin and coelenterazine analoguesBiochemistry Journal296(Pt 3)549-551(1993) 3.Pichler, A., Prior, J.L., and Piwnica-Worms, D.Imaging reversal of multidrug resistance in living mice with bioluminescence: MDR1 P-glycoprotein transports coelenterazineProc. Natl. Acad. Sci. USA.101(6)1702-1707(2004)

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, pentasodium salt 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.

Rhod-FF is a difluorinated analog of the cell-impermeant calcium indicator rhod-2. It has a very low affinity for calcium (Kd = 320 μM). Low affinity calcium indicators are particularly useful for studying compartments with high concentrations of calcium, such as endoplasmic reticulum, where high affinity dyes will be insensitive to luminal fluctuations. Rhod-FF has excitation emission maxima of approximately 552 and 580 nm, respectively.

Indo-1 (sodium salt) is a ratiometric fluorescent calcium indicator. It is ideal for analyses using flow cytometry, as it uses a single excitation source, typically 349-364 nm light from an argon-ion laser. The emission maximum shifts from 475-485 nm without calcium to 400-410 nm when Indo-1 (sodium salt) binds calcium. Indo-1 (sodium salt) is prone to photobleaching, which limits its usefulness in methods involving microscopy.

Fluo-3 is a fluorescent calcium indicator commonly used in flow cytometry and cell-based experiments to detect changes in intracellular calcium levels. Its absorption maximum at 506 nm makes it compatible with excitation at 488 nm by argon-ion laser sources. Fluo-3 provides intense fluorescence upon binding calcium, detected at a maximum emission at 526 nm which can be monitored by FL1 (green, 525 nm band pass) sensors in flow cytometry.

Fluo-3AM is a calcium indicator that exhibits an increase in fluorescence upon binding Ca2+. It is used to image the spatial dynamics of Ca2+ signaling in flow cytometry experiments.

Indo-1 (potassium salt) is a ratiometric fluorescent calcium indicator. It is ideal for analyses using flow cytometry, as it uses a single excitation source, typically 349-364 nm light from an argon-ion laser. The emission maximum shifts from 475-485 nm without calcium to 400-410 nm when Indo-1 (potassium salt) binds calcium. Indo-1 (potassium salt) is prone to photobleaching, which limits its usefulness in methods involving microscopy.

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, pentapotassium salt 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.

BAPTA Tetrasodium is a selective fluorescent chelator for calcium. In conjunction with certain formazan dyes, BAPTA can be used in a colorimetric assay for Mg2+.

Fluo-4 AM is a fluorescent dye (λex=494 nm, λem=516 nm).

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, pentasodium salt is most commonly used among the visible light-excitable calcium indicators.

Quin-2 is a high-affinity fluorescent calcium indicator (Kd = 115 nM for calcium). It displays high selectivity for calcium, as it is not affected by sodium gradients, membrane potential, or intracellular pH. High affinity probes like quin-2 are ideal for monitoring low levels of calcium, as are found in resting cells. Loadings of up to 2 mM quin-2 are without serious toxic effects, so quin-2 may be used to buffer intracellular calcium transients. Excitation emission maxima for quin-2 are 339 and 492 nm, respectively.

Fura-FF AM is a cell-permeable acetoxymethyl ester of the fluorescence calcium indicator fura-FF (potassium salt). Upon entering cells, it is hydrolyzed by intracellular esterases to produce fura-FF, a difluorinated derivative of the calcium indicator fura-2. Unlike fura-2, fura-FF has negligible magnesium sensitivity, reducing interference from this cation, and a higher calcium dissociation constant (Kd(calcium) = 6 μM for fura-FF and 0.14 μM for fura-2). The spectral properties of fura-FF are similar to those of fura-2, with fura-FF displaying excitation emission spectra of 365 514 nm in the absence of calcium and shifting to 339 507 nm in the presence of high calcium concentrations. Low affinity calcium dyes, including fura-FF, are preferred for studying compartments with high calcium concentrations, such as mitochondria, or in cell systems with relatively low calcium buffering capacities, such as neuronal dendrites and spines.

Fura-2 AM is an indicator of ratiometric fluorescent Ca2+.

Rhod-5N is a low affinity fluorescent calcium probe (Kd = 320 μM). Low affinity calcium indicators are particularly useful for studying compartments with high concentrations of calcium, such as endoplasmic reticulum, where high affinity dyes will be insensitive to luminal fluctuations. Rhod-5N has excitation emission maxima of approximately 551 and 576 nm, respectively

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, pentapotassium salt is most commonly used among the visible light-excitable calcium indicators.

Rhod-2 (sodium salt) is a water-soluble, red fluorescent calcium indicator. It exhibits a significant shift in fluorescence intensity upon calcium binding (ex max = 549 nm; calcium-free v. ex em max = 552 581 nm; calcium-bound). [1][2] Unlike the UV-excitable indicators fura-2 and indo-1 , there is no accompanying spectral shift.

Indo-1 AM is an indicator of fluorescent Ca2+ (λex=340 nm, λem=405 485 nm).