AAT Bioquest

Protonex™ Red 600

The pH dependent Emission spectra of Protonex™ Red 600.
The pH dependent Emission spectra of Protonex™ Red 600.
The pH dependent Emission spectra of Protonex™ Red 600.
Ordering information
Catalog Number
Unit Size
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Additional ordering information
InternationalSee distributors
ShippingStandard overnight for United States, inquire for international
Physical properties
Molecular weight698.94
Spectral properties
Excitation (nm)576
Emission (nm)597
Storage, safety and handling
H-phraseH303, H313, H333
Hazard symbolXN
Intended useResearch Use Only (RUO)
R-phraseR20, R21, R22
StorageFreeze (< -15 °C); Minimize light exposure


Molecular weight
Excitation (nm)
Emission (nm)
Protonex™ Red dye demonstrated pH-dependent fluorescence. Unlike most of the existing fluorescent dyes that are more fluorescent at higher pH, acidic conditions enhance the fluorescence of Protonex™ Red dye. The fluorescence of Protonex™ Red dye dramatically increases as pH decreases from neutral to the acidic. The weak fluorescence outside the cell may potentially eliminates the wash steps. Protonex™ Red dye provides a powerful tool to monitor acidic cell compartments such as endosomes and lysosomes. Protonex™ Red dye is weakly fluorescent outside the cells, but its fluorescence is significantly enhanced in acidic compartments (such as phagosomes, lysosomes and endosomes). This Protonex™ Red enables the specific detection of cellular acidic compartments with reduced signal variability and improved accuracy for imaging or flow applications. It can be also used for multiplexing cellular functional analysis with green dyes such as GFP, Fluo-8, calcein, or FITC-labeled antibodies. Protonex™ Red has the spectral properties similar to those of Texas Red, making the common filter set of Texas Red readily available to the assays of Protonex™ Red.


Common stock solution preparation

Table 1. Volume of DMSO needed to reconstitute specific mass of Protonex™ Red 600 to given concentration. Note that volume is only for preparing stock solution. Refer to sample experimental protocol for appropriate experimental/physiological buffers.

0.1 mg0.5 mg1 mg5 mg10 mg
1 mM143.074 µL715.369 µL1.431 mL7.154 mL14.307 mL
5 mM28.615 µL143.074 µL286.148 µL1.431 mL2.861 mL
10 mM14.307 µL71.537 µL143.074 µL715.369 µL1.431 mL

Molarity calculator

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Spectral properties

Excitation (nm)576
Emission (nm)597



View all 5 citations: Citation Explorer
Brain injury accelerates the onset of a reversible age-related microglial phenotype associated with inflammatory neurodegeneration
Authors: Ritzel, Rodney M and Li, Yun and Jiao, Yun and Lei, Zhuofan and Doran, Sarah J and He, Junyun and Shahror, Rami A and Henry, Rebecca J and Khan, Romeesa and Tan, Chunfeng and others,
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Journal: Glia (2021): 746--764
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Authors: Guentsch, Annemarie and Beneke, Angelika and Swain, Lija and Farhat, Katja and Nagarajan, Shunmugam and Wielockx, Ben and Raithatha, Kaamini and Dudek, Jan and Rehling, Peter and Zieseniss, Anke and others, undefined
Journal: Molecular and Cellular Biology (2016): MCB--00236


View all 56 references: Citation Explorer
Monitoring phospholipid dynamics during phagocytosis: application of genetically-encoded fluorescent probes
Authors: Sarantis H, Grinstein S.
Journal: Methods Cell Biol (2012): 429
Phagocytosis and digestion of pH-sensitive fluorescent dye (Eos-FP) transfected E. coli in whole blood assays from patients with severe sepsis and septic shock
Authors: Schreiner L, Huber-Lang M, Weiss ME, Hohmann H, Schmolz M, Schneider EM.
Journal: J Cell Commun Signal (2011): 135
The application of fluorescent probes for the analysis of lipid dynamics during phagocytosis
Authors: Flannagan RS, Grinstein S.
Journal: Methods Mol Biol (2010): 121
Quantification of microsized fluorescent particles phagocytosis to a better knowledge of toxicity mechanisms
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Journal: Inhal Toxicol (2010): 1091
Analysis of macrophage phagocytosis: quantitative assays of phagosome formation and maturation using high-throughput fluorescence microscopy
Authors: Steinberg BE, Grinstein S.
Journal: Methods Mol Biol (2009): 45
Phagocytosis and postphagocytic reaction of cord blood and adult blood monocyte after infection with green fluorescent protein-labeled Escherichia coli and group B Streptococci
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Journal: Cytometry B Clin Cytom (2009): 271
A fluorescently tagged C-terminal fragment of p47phox detects NADPH oxidase dynamics during phagocytosis
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Journal: Mol Biol Cell (2009): 1520
Analysis of phosphoinositide dynamics during phagocytosis using genetically encoded fluorescent biosensors
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Journal: Methods Mol Biol (2008): 287
Development of a highly specific rhodamine-based fluorescence probe for hypochlorous acid and its application to real-time imaging of phagocytosis
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