Fluo-8H™, AM
Ordering information
Price | |
Catalog Number | |
Unit Size | |
Quantity |
Additional ordering information
Telephone | 1-800-990-8053 |
Fax | 1-800-609-2943 |
sales@aatbio.com | |
Quotation | Request |
International | See distributors |
Shipping | Standard overnight for United States, inquire for international |
Physical properties
Dissociation constant (Kd, nM) | 232 |
Molecular weight | 1074.98 |
Solvent | DMSO |
Spectral properties
Correction Factor (260 nm) | 1.076 |
Correction Factor (280 nm) | 0.769 |
Extinction coefficient (cm -1 M -1) | 23430 |
Excitation (nm) | 495 |
Emission (nm) | 516 |
Quantum yield | 0.161 |
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); Minimize light exposure |
UNSPSC | 12352200 |
Related products
Overview | ![]() ![]() |
See also: Calcium Indicators, Chemical Reagents, Classic Dyes, Fluo-8, Fluoresceins, Intracellular Ions, Physiological Probes
Molecular weight 1074.98 | Dissociation constant (Kd, nM) 232 | Correction Factor (260 nm) 1.076 | Correction Factor (280 nm) 0.769 | Extinction coefficient (cm -1 M -1) 23430 | Excitation (nm) 495 | Emission (nm) 516 | Quantum yield 0.161 |
Calcium measurements are critical for numerous biological investigations. Fluorescent probes that show spectral responses upon binding Ca2+ have enabled researchers to investigate changes in intracellular free Ca2+ concentrations by using fluorescence microscopy, flow cytometry, fluorescence spectroscopy, and fluorescence microplate readers. Fluo-3 AM and Fluo-4 AM are most commonly used among the visible light-excitable calcium indicators for live-cell calcium imaging. However, Fluo-3 AM and Fluo-4 AM are only moderately fluorescent in live cells upon esterase hydrolysis and require harsh cell loading conditions to maximize their cellular calcium responses. Fluo-8® dyes are developed to improve cell loading and calcium response while maintaining the convenient Fluo-3 and Fluo-4 spectral wavelengths of Ex/Em = ∼490/∼520 nm. Fluo-8® AM can be loaded into cells at room temperature, while Fluo-3 AM and Fluo-4 AM require 37°C for cell loading. In addition, Fluo-8® AM is two times brighter than Fluo-4 AM and four times brighter than Fluo-3 AM. AAT Bioquest offers a set of our outstanding Fluo-8® reagents with different calcium-binding affinities (Fluo-8® Kd = 389 nM; Fluo-8H™ Kd = 232 nM; Fluo-8L™ Kd = 1.86 µM; Fluo-8FF™ Kd = 10 µM). We also offer versatile packing sizes to meet your special needs (e.g., 1 mg, 10x50 µg, 20x50 µg, and HTS packages) with no additional packaging charge.
Platform
Fluorescence microscope
Excitation | FITC |
Emission | FITC |
Recommended plate | Black wall/clear bottom |
Fluorescence microplate reader
Excitation | 490 |
Emission | 525 |
Cutoff | 515 |
Recommended plate | Black wall/clear bottom |
Instrument specification(s) | Bottom read mode/Programmable liquid handling |
Example protocol
PREPARATION OF STOCK SOLUTIONS
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.
Fluo-8H™ AM Stock Solution
Prepare a 2 to 5 mM stock solution of Fluo-8H™ AM in high-quality, anhydrous DMSO.PREPARATION OF WORKING SOLUTION
Fluo-8H™ AM Working Solution
On the day of the experiment, either dissolve Fluo-8H™ AM in DMSO or thaw an aliquot of the indicator stock solution to room temperature. Prepare a dye working solution of 2 to 20 µM in a buffer of your choice (e.g., Hanks and Hepes buffer) with 0.04% Pluronic® F-127. For most cell lines, Fluo-8H™ 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 Fluo-8H™ 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 solution, can be purchased from AAT Bioquest.
SAMPLE EXPERIMENTAL PROTOCOL
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.
- Prepare cells in growth medium overnight.
- On the next day, add 1X Fluo-8H™ AM working solution into your cell plate.
Note If your compound(s) interfere with the serum, replace the growth medium with fresh HHBS buffer before dye-loading. - Incubate the dye-loaded plate in a cell incubator at 37 °C for 30 to 60 minutes.
Note Incubating the dye for longer than 2 hours can improve signal intensities in certain cell lines. - 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.
- Add the stimulant as desired and simultaneously measure fluorescence using either a fluorescence microscope equipped with a FITC filter set or a fluorescence plate reader containing a programmable liquid handling system such as an FDSS, FLIPR, or FlexStation, at 490/525 nm cutoff 515 nm.
Calculators
Common stock solution preparation
Table 1. Volume of DMSO needed to reconstitute specific mass of Fluo-8H™, AM 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 | 93.025 µL | 465.125 µL | 930.25 µL | 4.651 mL | 9.302 mL |
5 mM | 18.605 µL | 93.025 µL | 186.05 µL | 930.25 µL | 1.86 mL |
10 mM | 9.302 µL | 46.512 µL | 93.025 µL | 465.125 µL | 930.25 µL |
Molarity calculator
Enter any two values (mass, volume, concentration) to calculate the third.
Mass (Calculate) | Molecular weight | Volume (Calculate) | Concentration (Calculate) | Moles | ||||
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Spectrum
Open in Advanced Spectrum Viewer


Spectral properties
Correction Factor (260 nm) | 1.076 |
Correction Factor (280 nm) | 0.769 |
Extinction coefficient (cm -1 M -1) | 23430 |
Excitation (nm) | 495 |
Emission (nm) | 516 |
Quantum yield | 0.161 |
Product Family
Name | Excitation (nm) | Emission (nm) | Quantum yield |
Fluo-8®, AM | 495 | 516 | 0.161 |
Fluo-8L™, AM | 495 | 516 | 0.161 |
Fluo-8FF™, AM | 495 | 516 | 0.161 |
Fluo-4 AM *Ultrapure Grade* *CAS 273221-67-3* | 495 | 528 | 0.161 |
Fluo-3, AM *CAS 121714-22-5* | 507 | 516 | 0.151 |
Fluo-3, AM *UltraPure grade* *CAS 121714-22-5* | 507 | 516 | 0.151 |
Fluo-3, AM *Bulk package* *CAS 121714-22-5* | 507 | 516 | 0.151 |
Fluo-3FF, AM *UltraPure grade* *Cell permeant* | 507 | 516 | 0.151 |
Fluo-5F, AM *Cell permeant* | 494 | 516 | - |
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Images

Figure 1. U2OS cells were seeded overnight at 40,000 cells per 100 uL per well in a 96-well black all/clear bottom costar plate. The growth medium was removed, and the cells were incubated with 100 uL of 4 uM Fluo-3 AM, Fluo-4 AM or Fluo-8® AM in HHBS at 37 °C for 1 hour. The cells were washed twice with 200 uL HHBS, then imaged with a fluorescence microscope using FITC channel.
Citations
View all 172 citations: Citation Explorer
The Roles of Two CNG Channels in the Regulation of Ascidian Sperm Chemotaxis
Authors: Shiba, Kogiku and Inaba, Kazuo
Journal: International Journal of Molecular Sciences (2022): 1648
Authors: Shiba, Kogiku and Inaba, Kazuo
Journal: International Journal of Molecular Sciences (2022): 1648
Crosstalk between ENaC and basolateral Kir4. 1/Kir5. 1 channels in the cortical collecting duct
Authors: Isaeva, Elena and Bohovyk, Ruslan and Fedoriuk, Mykhailo and Shalygin, Alexey and Klemens, Christine A and Zietara, Adrian and Levchenko, Vladislav and Denton, Jerod S and Staruschenko, Alexander and Palygin, Oleg
Journal: British journal of pharmacology (2021)
Authors: Isaeva, Elena and Bohovyk, Ruslan and Fedoriuk, Mykhailo and Shalygin, Alexey and Klemens, Christine A and Zietara, Adrian and Levchenko, Vladislav and Denton, Jerod S and Staruschenko, Alexander and Palygin, Oleg
Journal: British journal of pharmacology (2021)
Correlation between calcium signaling and ATP release mediated by connexin hemichannels in different mouse models of disease
Authors: Mazzarda, Flavia
Journal: (2021)
Authors: Mazzarda, Flavia
Journal: (2021)
Development of vibration mechanical stimuli loading device for live cell fluorescence microscopy
Authors: SATO, Katsuya and OOMORI, Daiki
Journal: Journal of Biomechanical Science and Engineering (2021): 21--00294
Authors: SATO, Katsuya and OOMORI, Daiki
Journal: Journal of Biomechanical Science and Engineering (2021): 21--00294
Organ-on-chip model shows that ATP release through connexin hemichannels drives spontaneous Ca 2+ signaling in non-sensory cells of the greater epithelial ridge in the developing cochlea
Authors: Mazzarda, Flavia and D'Elia, Annunziata and Massari, Roberto and De Ninno, Adele and Bertani, Francesca Romana and Businaro, Luca and Ziraldo, Gaia and Zorzi, Veronica and Nardin, Chiara and Peres, Chiara and others,
Journal: Lab on a Chip (2020): 3011--3023
Authors: Mazzarda, Flavia and D'Elia, Annunziata and Massari, Roberto and De Ninno, Adele and Bertani, Francesca Romana and Businaro, Luca and Ziraldo, Gaia and Zorzi, Veronica and Nardin, Chiara and Peres, Chiara and others,
Journal: Lab on a Chip (2020): 3011--3023
Localization of sperm intracellular Ca2+ keeps fertilizability in the newt vas deferens
Authors: Makino, Nanae and Sato, Nozomi and Takayama-Watanabe, Eriko and Watanabe, Akihiko
Journal: Reproduction (2020): 339--349
Authors: Makino, Nanae and Sato, Nozomi and Takayama-Watanabe, Eriko and Watanabe, Akihiko
Journal: Reproduction (2020): 339--349
A motogenic GABAergic system of mononuclear phagocytes facilitates dissemination of coccidian parasites
Authors: Bhandage, Amol K and Olivera, Gabriela C and Kanatani, Sachie and Thompson, Elizabeth and Lor{\'e}, Karin and Varas-Godoy, Manuel and Barragan, Antonio
Journal: Elife (2020): e60528
Authors: Bhandage, Amol K and Olivera, Gabriela C and Kanatani, Sachie and Thompson, Elizabeth and Lor{\'e}, Karin and Varas-Godoy, Manuel and Barragan, Antonio
Journal: Elife (2020): e60528
A Distinct Role of the Autonomic Nervous System in Modulating the Function of Lymphatic Vessels under Physiological and Tumor-Draining Conditions
Authors: Bachmann, Samia B and Gsponer, Denise and Montoya-Zegarra, Javier A and Schneider, Martin and Scholkmann, Felix and Tacconi, Carlotta and Noerrelykke, Simon F and Proulx, Steven T and Detmar, Michael
Journal: Cell reports (2019): 3305--3314
Authors: Bachmann, Samia B and Gsponer, Denise and Montoya-Zegarra, Javier A and Schneider, Martin and Scholkmann, Felix and Tacconi, Carlotta and Noerrelykke, Simon F and Proulx, Steven T and Detmar, Michael
Journal: Cell reports (2019): 3305--3314
Droplet microfluidic systems for formation and studies of lipid bilayers
Authors: Czekalska, Magdalena Anna
Journal: (2019)
Authors: Czekalska, Magdalena Anna
Journal: (2019)
Electrode-free nanopore sensing by DiffusiOptoPhysiology
Authors: Wang, Yuqin and Wang, Yu and Du, Xiaoyu and Yan, Shuanghong and Zhang, Panke and Chen, Hong-Yuan and Huang, Shuo
Journal: Science Advances (2019): eaar3309
Authors: Wang, Yuqin and Wang, Yu and Du, Xiaoyu and Yan, Shuanghong and Zhang, Panke and Chen, Hong-Yuan and Huang, Shuo
Journal: Science Advances (2019): eaar3309
Application notes
A Comparison of Fluorescent Red Calcium Indicators for Detecting Intracellular Calcium Mobilization in CHO Cells
A Meta-Analysis of Common Calcium Indicators
A New Red Fluorescent & Robust Screen Quest™ Rhod-4™ Ca2+Indicator for Screening GPCR & Ca2+ Channel Targets
A New Robust No-Wash FLIPR Calcium Assay Kit for Screening GPCR and Calcium Channel Targets
A Novel NO Wash Probeniceid-Free Calcium Assay for Functional Analysis of GPCR and Calcium Channel Targets
A Meta-Analysis of Common Calcium Indicators
A New Red Fluorescent & Robust Screen Quest™ Rhod-4™ Ca2+Indicator for Screening GPCR & Ca2+ Channel Targets
A New Robust No-Wash FLIPR Calcium Assay Kit for Screening GPCR and Calcium Channel Targets
A Novel NO Wash Probeniceid-Free Calcium Assay for Functional Analysis of GPCR and Calcium Channel Targets
FAQ
Are there any calcium indicators that don't require probenecid (PBC)?
Are there upgraded trypan blue derivatives for cell viability testing?
Can I intracellularly measure mitochondria calcium flux and changes in mitochondria membrane potential at the same time?
Do you offer any products for measuring intracellular calcium concentration or movement by flow cytometry?
How do I make an AM ester stock solution?
Are there upgraded trypan blue derivatives for cell viability testing?
Can I intracellularly measure mitochondria calcium flux and changes in mitochondria membrane potential at the same time?
Do you offer any products for measuring intracellular calcium concentration or movement by flow cytometry?
How do I make an AM ester stock solution?