pHrodo™ Red Avidin (Fluorogenic pH Sensor)

Catalog number:  P35362

Related applications:

Cell Viability, Proliferation & Function

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pHrodo® Red Avidin is a conjugate of avidin and pHrodo® Red dye, a novel, fluorogenic dye that dramatically increases in fluorescence as the pH of its surroundings become more acidic. pHrodo® Red dye conjugates are non-fluorescent outside the cell, but fluoresce bright red in phagosomes, making them ideal tools for studies ranging from phagocytosis of bioparticles to receptor internalization. Original pHrodo® and pHrodo® Red dye are the same molecule.

With pHrodo® Red Avidin Fluorogenic pH Sensor You Get:
• Specific detection of phagocytosis and endocytosis
• Faster staining
• More accurate results in sensitive experiments
• Multiplexing capability with green dyes
• Validation in flow cytometry, imaging, HTS, and HCS

Get Better Results in Endocytosis Studies
Endocytosis and phagocytosis underly physiological events ranging from host-pathogen response to receptor desensitization via internalization as is common in the GPCR class of receptors). Once internalized, material can be acidified in endosomes or lysosomes. Our pHrodo® Red dye fluorogenic pH sensitive probe, when conjugated to target molecules, allows direct visual monitoring of material entering these acidic compartments. At neutral and basic pH values, pHrodo® Red dye emission is at its minimum; with acidification, pHrodo® Red dye emission is increased by as much as 8-fold (at pH 4). The red fluorescence of pHrodo® Red Avidin is ideal for multiplexing applications with green-fluorescent compounds such GFP, Fluo-4, or calcein.

Faster and More Accurate Staining in Multiple Validated Applications
pHrodo® Red Avidin offers reduced signal variability and improved timing compared to ratiometric dyes like BCECF and SNARF, and the lack of fluorescence outside the cell eliminates the need for wash steps and quencher dyes. The fluorescence of pHrodo® Red dye is dimmed by complete media and whole blood, further improving the signal-to-noise ratio. pHrodo® Red has been cited in over 150 publications and is validated in flow cytometry, high throughput screening (HTS), high content screening (HCS), and other imaging applications.

Easy Biotinylation Lets You Enjoy Flexibility in Experimental Design
The pHrodo® Red Avidin reagent can quickly be coupled to any biotinlyated reagent, including many of our own biotin conjugates of antibodies, proteins, and toxins including transferrin, EGF, and cholera toxin. Alternatively, you can create your own biotinylated target either by using Click-iT® chemistry to metabolically incorporate an alkyne biotin, or by using any of our biotin labeling kits.

Alternative Conjugation Chemistry to pHrodo® SE
In cases where the amine reactive pHrodo-SE conjugates show reduced or complete loss of function, biotin and avidin conjugation can be considered using pHrodo® Red Avidin. In one example, pHrodo-EGF was created using the avidin-biotin approach and shown to bind its receptor and be internalized (Ref 1).

For Research Use Only. Not intended for any animal or human therapeutic or diagnostic use.


1. Suprynowicz FA, Krawczyk E, Hebert JD, Sudarshan SR, Simic V, Kamonjoh CM, Schlegel R. The human papillomavirus type 16 E5 oncoprotein inhibits epidermal growth factor trafficking independently of endosome acidification. J Virol. 2010 Oct;84(20):10619-29. PubMed PMID: 20686024
For Research Use Only. Not for use in diagnostic procedures.


Shipping Condition: Room Temperature
Product Line: Molecular Probes™, pHrodo™
Label or Dye: pHrodo™ Red

Contents & storage

Store at ≤-20°C

Desiccate and protect from light