BCECF, AM
Intracellular pH plays an important modulating role in many cellular events, including cell growth, calcium regulation, enzymatic activity, receptor-mediated signal transduction, ion transport, endocytosis, chemotaxis, cell adhesion and other cellular processes. pH-sensitive fluorescent dyes have been widely applied to monitor changes in intracellular pH in recent years. Imaging techniques that use fluorescent pH indicators also allow researchers to investigate these processes with much greater spatial resolution and sampling density that can be achieved using other technologies such as microelectrode. Among them, 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF) is the most popular pH probe since it can be used to monitor cellular pH ratiometrically. BCECF AM is the cell-permeable version of BCECF.
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.
BCECF AM Stock Solution
Prepare a 2 to 20 mM stock solution of BCECF AM in high-quality, anhydrous DMSO.PREPARATION OF WORKING SOLUTION
BCECF AM Working Solution
On the day of the experiment, either dissolve BCECF AM in DMSO or thaw an aliquot of the indicator stock solution to room temperature. Prepare a BCECF AM working solution of 5 to 50 µM in a buffer of your choice (e.g., Hanks and Hepes buffer).Note The nonionic detergent Pluronic® F-127 can be used to increase the aqueous solubility of AM esters. In the staining buffer, the final Pluronic® F-127 concentration should be approximately 0.02%. A variety of Pluronic® F-127 products can be purchased from AAT Bioquest. Avoid long-term storage of AM esters in the presence of Pluronic® F-127.
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
The following is a recommended protocol for loading BCECF AM into live mammalian cells. This protocol only provides a guideline, should be modified according to your specific needs.
- Prepare viable cells as desired.
- On the next day, add 100 µL/well (96-well plate) or 25 µL/well (384-well plate) of the BCECF AM working solution into the cell plate.
Note If your compound(s) interfere with the serum, replace the growth medium with fresh HHBS buffer (100 μL/well for 96-well plate or 25 μL/well for 384-well plate) before dye-loading. - Incubate the dye-loaded plate in a cell incubator at 37 °C for 30 to 60 minutes.
- Replace the dye working solution with HHBS or buffer of your choice to remove any excess probes.
- Prepare the compound plates using HHBS or a buffer of your choice.
- Run the pH assay as desired and simultaneously measure fluorescence using either a fluorescence microscope equipped with a FITC filter set or a fluorescence plate reader at Ex/Em = 490/535 nm cutoff 515 nm. For ratio measurements, monitor fluorescence at Ex/Em1 = 430/535 nm cutoff 515 nm and Ex/Em2 = 505/535 nm cutoff 515 nm.
Note The compound addition is 50 μL/well (96-well plate) or 25 μL/well (384-well plate).
Note Assays should be completed within 3 to 5 minutes after compound addition. However, a minimum of 8 minutes is recommended for data collection.
Calculators
Common stock solution preparation
Table 1. Volume of DMSO needed to reconstitute specific mass of BCECF, 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 | 123.657 µL | 618.284 µL | 1.237 mL | 6.183 mL | 12.366 mL |
5 mM | 24.731 µL | 123.657 µL | 247.314 µL | 1.237 mL | 2.473 mL |
10 mM | 12.366 µL | 61.828 µL | 123.657 µL | 618.284 µL | 1.237 mL |
Molarity calculator
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Spectrum
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Citations
View all 2 citations: Citation Explorer
The F0F1 ATP synthase regulates human neutrophil migration through cytoplasmic proton extrusion coupled with ATP generation
Authors: Gao, Jun and Zhang, Tian and Kang, Zhanfang and Ting, Weijen and Xu, Lingqing and Yin, Dazhong
Journal: Molecular Immunology (2017): 219--226
Authors: Gao, Jun and Zhang, Tian and Kang, Zhanfang and Ting, Weijen and Xu, Lingqing and Yin, Dazhong
Journal: Molecular Immunology (2017): 219--226
Oxidative Stress-Activated NHE1 Is Involved in High Glucose-Induced Apoptosis in Renal Tubular Epithelial Cells
Authors: Wu, Yiqing and Zhang, Min and Liu, Rui and Zhao, Chunjie
Journal: Yonsei Medical Journal (2016): 1252--1259
Authors: Wu, Yiqing and Zhang, Min and Liu, Rui and Zhao, Chunjie
Journal: Yonsei Medical Journal (2016): 1252--1259
References
View all 34 references: Citation Explorer
Simultaneous measurement of water volume and pH in single cells using BCECF and fluorescence imaging microscopy
Authors: Alvarez-Leefmans FJ, Herrera-Perez JJ, Marquez MS, Blanco VM.
Journal: Biophys J (2006): 608
Authors: Alvarez-Leefmans FJ, Herrera-Perez JJ, Marquez MS, Blanco VM.
Journal: Biophys J (2006): 608
Photophysics of the fluorescent pH indicator BCECF
Authors: Boens N, Qin W, Basaric N, Orte A, Talavera EM, Alvarez-Pez JM.
Journal: J Phys Chem A Mol Spectrosc Kinet Environ Gen Theory (2006): 9334
Authors: Boens N, Qin W, Basaric N, Orte A, Talavera EM, Alvarez-Pez JM.
Journal: J Phys Chem A Mol Spectrosc Kinet Environ Gen Theory (2006): 9334
Drug efflux transport properties of 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein acetoxymethyl ester (bcecf-am) and its fluorescent free acid, bcecf
Authors: Bachmeier CJ, Trickler WJ, Miller DW.
Journal: J Pharm Sci (2004): 932
Authors: Bachmeier CJ, Trickler WJ, Miller DW.
Journal: J Pharm Sci (2004): 932
A rapid method for measuring intracellular pH using BCECF-AM
Authors: Ozkan P, Mutharasan R.
Journal: Biochim Biophys Acta (2002): 143
Authors: Ozkan P, Mutharasan R.
Journal: Biochim Biophys Acta (2002): 143
Detection of MRP functional activity: calcein AM but not BCECF AM as a Multidrug Resistance-related Protein (MRP1) substrate
Authors: Olson DP, Taylor BJ, Ivy SP.
Journal: Cytometry (2001): 105
Authors: Olson DP, Taylor BJ, Ivy SP.
Journal: Cytometry (2001): 105
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