Shop All Phagocytosis Kits & Phagocytic Particles

Vybrant™ Phagocytosis Assay Kit (Invitrogen™)

The Vybrant® Phagocytosis Assay Kit provides a way for researchers to observe and quantitate the process of phagocytosis in human polynuclear cells and mouse macrophages by following the internalization of a foreign particle—in this case killed E. coli (K-12 strain) cells that have been labeled with the fluorescent dye fluorescein. In addition to the lyophilized E. coli BioParticles® component, the kit contains a trypan blue solution (to quench the fluorescence from particles that were not internalized) as well as step-by-step instructions for performing this phagocytosis assay in a fluorescence microplate reader. The methodology used with this kit has been developed using an adherent murine macrophage cell line (J774); however, by modifying the cell culture conditions, researchers can adapt this phagocytosis assay to other adherent cell lines.

Vybrant® Phagocytosis Assay Kit Specifications:
• Particles are fluorescein-labeled E. coli (K-12 strain)
• Kit supplies sufficient reagents for ~250 tests using 96-well plates
• Fluorescence is measured using a microplate reader (Ex/Em ~480/520 nm)


Find More BioParticles® Products
We offer a large range of dye-labeled and unlabeled E. coli (K-12 strain), S. aureus (Wood strain, without protein A), and zymosan (S. cerevisiae) BioParticles® products. Find out about these products and their applications by reviewing Probes for Following Receptor Binding and Phagocytosis—Section 16.1 in the Molecular Probes® Handbook.

For pH-sensitive endocytosis assays, see our pHrodo™ BioParticles® conjugates.

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

pHrodo™ Green S. aureus Bioparticles™ Conjugate for Phagocytosis (Invitrogen™)

New pH-sensitive pHrodo® Green dye conjugates, like our pHrodo® Red dye conjugates, give faster and more accurate results than any other phagocytosis assay. pHrodo® Green conjugates are non-fluorescent outside the cell at neutral pH, but fluoresce brightly green at acidic pH such as in phagosomes. Get faster staining and more accurate results—without the need for wash steps or quencher dye.

• Specific detection of phagocytosis and endocytosis
• Reduced signal variability and improved timing in sensitive experiments
• Enough to do 100 tests when using 100 µL in each well of a 96-well plate
• Multiplex with other compatible dyes, such as red florescent protein, TMRM, NucBlue™ Hoechst, and CellROX® Deep Red

The fluorescence of the novel pHrodo® Green dye dramatically increases as pH decreases from neutral to acidic, making it an ideal tool to study phagocytosis and its regulation by drugs and/or environmental factors. The lack of fluorescence outside the cell eliminates the need for wash steps and quencher dyes.

Use the ready-made pHrodo® Green S. aureus BioParticles® Conjugate in imaging, high content screening, high throughput screening, and flow applications. pHrodo® Green dye is also available as a conjugate of E. coli BioParticles®, zymosan BioParticles®, or dextran 10,000. To create other conjugates, such as antibody conjugates, use pHrodo® Green STP ester or pHrodo® Green maleimide.

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

Zymosan A S. cerevisiae BioParticles™, unlabeled (Invitrogen™)

The Molecular Probes® unlabeled BioParticles® product line comprises heat- or chemically killed S. aureus (Wood strain, without protein A) and zymosan (S. cerevisiae) cells. These nonfluorescent BioParticles® products are useful in phagocytosis assays, both as controls and for custom-labeling with reactive dyes.

BioParticles Specifications:
• Label (Ex/Em): Unlabeled
• Particle: Zymosan (S. cerevisiae)
Opsonizing reagent available


Using BioParticles® Products
BioParticles® conjugates are provided as lyophilized powders. There are approximately 3 x 108 S. aureus particles per mg solid and approximately 2 x 107 zymosan particles per mg solid. BioParticles® conjugates can be reconstituted in the buffer of your choice for use in phagocytosis assays.

Find More BioParticles® Products
We offer a large range of dye-labeled and unlabeled E. coli (K-12 strain), S. aureus (Wood strain, without protein A), and zymosan (S. cerevisiae) BioParticles® products. Find out about these products and their applications by reviewing Probes for Following Receptor Binding and Phagocytosis—Section 16.1 in the Molecular Probes® Handbook.

For pH-sensitive endocytosis assays, see our fluorescent pHrodo™ BioParticles® conjugates.

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

pHrodo™ Red S. aureus Bioparticles™ Conjugate for Phagocytosis (Invitrogen™)

New pH-sensitive pHrodo® Red dye conjugates give faster and more accurate results than any other phagocytosis assay pHrodo® Red dye conjugates are non-fluorescent outside the cell, but fluoresce brightly red in phagosomes.

Get faster staining and more accurate results without the need for wash steps or quencher dye
• Specific detection of phagocytosis and endocytosis
• Reduced signal variability and improved timing in sensitive experiments
• Multiplex with green dyes such as GFP, Fluo-4, or calcein

The fluorescence of the novel pHrodo® Red dye dramatically increases as pH decreases from neutral to the acidic, making it an ideal tool to study phagocytosis and its regulation by drugs and/or environmental factors. The lack of fluorescence outside the cell eliminates the need for wash steps and quencher dyes. Use the ready-made pHrodo® Red S. aureus BioParticles® conjugates in imaging or flow applications, or pHrodo® Red SE, the activated succinimidyl ester, for labeling microorganisms or proteins of your choice.

pHrodo™ Green Zymosan Bioparticles™ Conjugate for Phagocytosis (Invitrogen™)

New pH-sensitive pHrodo® Green dye conjugates, like our pHrodo® Red dye conjugates, give faster and more accurate results than any other phagocytosis assay. pHrodo® Green conjugates are non-fluorescent outside the cell at neutral pH, but fluoresce brightly green at acidic pH such as in phagosomes. Get faster staining and more accurate results—without the need for wash steps or quencher dye.

• Specific detection of phagocytosis and endocytosis
• Reduced signal variability and improved timing in sensitive experiments
• Enough to do 100 tests when using 100 µL in each well of a 96-well plate
• Multiplex with other compatible dyes, such as red florescent protein, TMRM, NucBlue™ Hoechst, and CellROX® Deep Red

The fluorescence of the novel pHrodo® Green dye dramatically increases as pH decreases from neutral to acidic, making it an ideal tool to study phagocytosis and its regulation by drugs and/or environmental factors. The lack of fluorescence outside the cell eliminates the need for wash steps and quencher dyes.

Use the ready-made pHrodo® Green Zymosan BioParticles® Conjugate in imaging, high content screening, high throughput screening, and flow applications. pHrodo® Green dye is also available as a conjugate of E. coli BioParticles®, S. aureus BioParticles®, or dextran 10,000. To create other conjugates, such as antibody conjugates, use pHrodo® Green STP ester or pHrodo® Green maleimide.

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

pHrodo™ Red E. coli BioParticles™ Conjugate for Phagocytosis (Invitrogen™)

New pH-sensitive pHrodo® dye conjugates give faster and more accurate results than any other phagocytosis assay.  pHrodo® dye conjugates are non-fluorescent outside the cell, but fluoresce brightly red in phagosomes.  Get faster staining and more accurate results—without the need for wash steps or quencher dye.

• Specific detection of phagocytosis and endocytosis
• Reduced signal variability and improved timing in sensitive experiments.
• Multiplex with green dyes such as GFP, Fluo-4, or calcein

The fluorescence of the novel pHrodo® dye dramatically increases as pH decreases from neutral to acidic, making it an ideal tool to study phagocytosis and its regulation by drugs and/or environmental factors. The lack of fluorescence outside the cell eliminates the need for wash steps and quencher dyes. Use the ready-made pHrodo® E.coli BioParticles® conjugates in imaging or flow applications, or pHrodo® SE, the activated succinimidyl ester, for labeling microorganisms or proteins of your choice.

Zymosan A BioParticles™ Opsonizing Reagent (Invitrogen™)

The zymosan A BioParticles® opsonizing agent is derived from highly purified rabbit polyclonal IgG antibodies and specifically designed to enhance the uptake of the zymosan A BioParticles® conjugates.

Escherichia coli (K-12 strain) BioParticles™, BODIPY™ FL conjugate (Invitrogen™)

The Molecular Probes® BioParticles® product line consists of a series of fluorescently labeled, heat- or chemically killed bacteria and yeast in a variety of sizes, shapes, and natural antigenicities. These fluorescent BioParticles® products have been employed to study phagocytosis by fluorescence microscopy, quantitative spectrofluorometry, and flow cytometry.

We offer E. coli (K-12 strain), S. aureus (Wood strain, without protein A) and zymosan (S. cerevisiae) BioParticles® conjugates covalently labeled with a variety of different fluorophores (special care has been taken to remove free dye after conjugation). Unlike the fluorescence of fluorescein-labeled BioParticles® conjugates, which is partially quenched in acidic environments, the fluorescence of the Alexa Fluor®, BODIPY® FL, tetramethylrhodamine and Texas Red® dye conjugates is uniformly intense over the pH range from 3 to 10.

BioParticles Specifications:
• Label (Ex/Em): BODIPY® FL (~505/513 nm)
• Particle: E. coli (K-12 strain)
Opsonizing reagent available


Using BioParticles Products
BioParticles® conjugates are provided as lyophilized powders. There are approximately 3 x 108 E. coli or S. aureus particles per mg solid and approximately 2 x 107 zymosan particles per mg solid. BioParticles® conjugates can be reconstituted in the buffer of your choice for use in phagocytosis assays. The fluorescence of BioParticles® conjugates that are bound to the surface of the cell (but not internalized) can be quenched by ethidium bromide, trypan blue, or other quenchers. In addition to cellular applications, fluorescent BioParticles® conjugates may be effective as flow cytometry calibration references when sorting bacteria and yeast mutants. These small particles may also be useful references for light scattering studies because their sizes and shapes differ in characteristic ways.

Find More BioParticles® Products
We offer a large range of dye-labeled and unlabeled E. coli (K-12 strain), S. aureus (Wood strain, without protein A), and zymosan (S. cerevisiae) BioParticles® products. Find out about these products and their applications by reviewing Probes for Following Receptor Binding and Phagocytosis—Section 16.1 in the Molecular Probes® Handbook.

For pH-sensitive endocytosis assays, see our pHrodo™ BioParticles® conjugates.

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

Zymosan A (S. cerevisiae) BioParticles™, Alexa Fluor™ 594 conjugate (Invitrogen™)

The Molecular Probes® BioParticles® product line consists of a series of fluorescently labeled, heat- or chemically killed bacteria and yeast in a variety of sizes, shapes, and natural antigenicities. These fluorescent BioParticles® products have been employed to study phagocytosis by fluorescence microscopy, quantitative spectrofluorometry, and flow cytometry.

We offer E. coli (K-12 strain), S. aureus (Wood strain, without protein A) and zymosan (S. cerevisiae) BioParticles® conjugates covalently labeled with a variety of different fluorophores (special care has been taken to remove free dye after conjugation). Unlike the fluorescence of fluorescein-labeled BioParticles® conjugates, which is partially quenched in acidic environments, the fluorescence of the Alexa Fluor®, BODIPY® FL, tetramethylrhodamine and Texas Red® dye conjugates is uniformly intense over the pH range from 3 to 10.

BioParticles Specifications:
• Label (Ex/Em): Alexa Fluor® 594 (~590/617 nm)
• Particle: Zymosan (S. cerevisiae)
Opsonizing reagent available


Using BioParticles Products
BioParticles® conjugates are provided as lyophilized powders. There are approximately 3 x 108 E. coli or S. aureus particles per mg solid and approximately 2 x 107 zymosan particles per mg solid. BioParticles® conjugates can be reconstituted in the buffer of your choice for use in phagocytosis assays. The fluorescence of BioParticles® conjugates that are bound to the surface of the cell (but not internalized) can be quenched by ethidium bromide, trypan blue, or other quenchers. In addition to cellular applications, fluorescent BioParticles® conjugates may be effective as flow cytometry calibration references when sorting bacteria and yeast mutants. These small particles may also be useful references for light scattering studies because their sizes and shapes differ in characteristic ways.

Find More BioParticles® Products
We offer a large range of dye-labeled and unlabeled E. coli (K-12 strain), S. aureus (Wood strain, without protein A), and zymosan (S. cerevisiae) BioParticles® products. Find out about these products and their applications by reviewing Probes for Following Receptor Binding and Phagocytosis—Section 16.1 in the Molecular Probes® Handbook.

For pH-sensitive endocytosis assays, see our pHrodo™ BioParticles® conjugates.

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

Staphylococcus aureus (Wood strain without protein A) BioParticles™, fluorescein conjugate (Invitrogen™)

The Molecular Probes® BioParticles® product line consists of a series of fluorescently labeled, heat- or chemically killed bacteria and yeast in a variety of sizes, shapes, and natural antigenicities. These fluorescent BioParticles® products have been employed to study phagocytosis by fluorescence microscopy, quantitative spectrofluorometry, and flow cytometry.

We offer E. coli (K-12 strain), S. aureus (Wood strain, without protein A) and zymosan (S. cerevisiae) BioParticles® conjugates covalently labeled with a variety of different fluorophores (special care has been taken to remove free dye after conjugation). Unlike the fluorescence of fluorescein-labeled BioParticles® conjugates, which is partially quenched in acidic environments, the fluorescence of the Alexa Fluor®, BODIPY® FL, tetramethylrhodamine and Texas Red® dye conjugates is uniformly intense over the pH range from 3 to 10.

BioParticles Specifications:
• Label (Ex/Em): Fluorescein (~494/518 nm)
• Particle: S. aureus (Wood strain, without protein A)
Opsonizing reagent available


Using BioParticles Products
BioParticles® conjugates are provided as lyophilized powders. There are approximately 3 x 108 E. coli or S. aureus particles per mg solid and approximately 2 x 107 zymosan particles per mg solid. BioParticles® conjugates can be reconstituted in the buffer of your choice for use in phagocytosis assays. The fluorescence of BioParticles® conjugates that are bound to the surface of the cell (but not internalized) can be quenched by ethidium bromide, trypan blue, or other quenchers. In addition to cellular applications, fluorescent BioParticles® conjugates may be effective as flow cytometry calibration references when sorting bacteria and yeast mutants. These small particles may also be useful references for light scattering studies because their sizes and shapes differ in characteristic ways.

Find More BioParticles® Products
We offer a large range of dye-labeled and unlabeled E. coli (K-12 strain), S. aureus (Wood strain, without protein A), and zymosan (S. cerevisiae) BioParticles® products. Find out about these products and their applications by reviewing Probes for Following Receptor Binding and Phagocytosis—Section 16.1 in the Molecular Probes® Handbook.

For pH-sensitive endocytosis assays, see our pHrodo™ BioParticles® conjugates.

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

Staphylococcus aureus (Wood strain without protein A) BioParticles™, Alexa Fluor™ 488 conjugate (Invitrogen™)

The Molecular Probes® BioParticles® product line consists of a series of fluorescently labeled, heat- or chemically killed bacteria and yeast in a variety of sizes, shapes, and natural antigenicities. These fluorescent BioParticles® products have been employed to study phagocytosis by fluorescence microscopy, quantitative spectrofluorometry, and flow cytometry.

We offer E. coli (K-12 strain), S. aureus (Wood strain, without protein A) and zymosan (S. cerevisiae) BioParticles® conjugates covalently labeled with a variety of different fluorophores (special care has been taken to remove free dye after conjugation). Unlike the fluorescence of fluorescein-labeled BioParticles® conjugates, which is partially quenched in acidic environments, the fluorescence of the Alexa Fluor®, BODIPY® FL, tetramethylrhodamine and Texas Red® dye conjugates is uniformly intense over the pH range from 3 to 10.

BioParticles Specifications:
• Label (Ex/Em): Alexa Fluor® 488 (~495/519 nm)
• Particle: S. aureus (Wood strain, without protein A)
Opsonizing reagent available


Using BioParticles Products
BioParticles® conjugates are provided as lyophilized powders. There are approximately 3 x 108 E. coli or S. aureus particles per mg solid and approximately 2 x 107 zymosan particles per mg solid. BioParticles® conjugates can be reconstituted in the buffer of your choice for use in phagocytosis assays. The fluorescence of BioParticles® conjugates that are bound to the surface of the cell (but not internalized) can be quenched by ethidium bromide, trypan blue, or other quenchers. In addition to cellular applications, fluorescent BioParticles® conjugates may be effective as flow cytometry calibration references when sorting bacteria and yeast mutants. These small particles may also be useful references for light scattering studies because their sizes and shapes differ in characteristic ways.

Find More BioParticles® Products
We offer a large range of dye-labeled and unlabeled E. coli (K-12 strain), S. aureus (Wood strain, without protein A), and zymosan (S. cerevisiae) BioParticles® products. Find out about these products and their applications by reviewing Probes for Following Receptor Binding and Phagocytosis—Section 16.1 in the Molecular Probes® Handbook.

For pH-sensitive endocytosis assays, see our pHrodo™ BioParticles® conjugates.

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

pHrodo™ Red Phagocytosis Particle Labeling Kit for Flow Cytometry (Invitrogen™)

• Specifically detect phagocytosis and endocytosis with pH-sensitive fluorogenic dye - discriminate endcytosed from adherent and extracellular particles
• Reduced signal variability and improved timing in sensitive experiments - no need for wash steps or quencher dye
• Bright red fluorescence - conveniently multiplex with green dyes such as GFP, Fluo-4, or calcein

View a selection guide for all pHrodo Indicators used in imaging, flow cytometry and microplate assays.

The pHrodo™ Red dye gives faster and more accurate results than any other phagocytosis assay

The new Molecular Probes™ proprietary pH-sensitive rhodamine-based pHrodo™ Red dye is non-fluorescent at neutral pH, but turns bright red upon acidification. Because it is both fluorogenic and pH-sensitive, the pHrodo™ Red dye can be used as a specific sensor of phagocytic events; acidification of the phagosome following phagocytosis is marked by red fluorescence. It is therefore an ideal tool with which to study phagocytosis and its regulation by drugs and/or environmental factors.

Rapid and reproducible

Wash steps and quencher dyes are not needed since the pHrodo™ Red dye is non-fluorescent outside the cell, making the staining protocol simple and fast. The elimination of wash steps and quencher dyes also improves assay reproducibility, particularly in plate reader-based assays.

Flexible applications

Use ready-made pHrodo™ Red BioParticles™ conjugates for convenient analysis of phagocytosis of Gram-positive or Gram-negative bacteria, or the amine-reactive pHrodo™ Red SE form for labeling microorganisms or proteins of your choice.

Compatible with multiple platforms
pHrodo™ Red dye conjugates can be used in plate readers, fluorescence microscopy imaging, and flow cytometry applications. The pHrodo™ Red Phagocytosis Particle Labeling Kit and the pHrodo™ Red E. coli BioParticles™ Phagocytosis Kit for flow cytometry were designed for rapid and convenient measurements of phagocytic activity in whole blood samples by flow cytometry. The kits include all the reagents required for assessing particle ingestion and red blood cell lysis. The Labeling Kit also contains the reagents required for labeling microorganisms with the pHrodo™ Red dye. Sufficient reagents are provided in both kits for approximately 100 assays.

The optimal absorption and fluorescence emission maxima of the pHrodo™ Red BioParticles™ conjugate is approximately 560 nm and 585 nm, respectively. However, the fluorophore is readily excited with the 488 nm argon-ion laser installed on most flow cytometers.

pHrodo™ Green E. coli BioParticles™ Conjugate for Phagocytosis (Invitrogen™)

New pH-sensitive pHrodo® Green dye conjugates, like our pHrodo® Red dye conjugates, give faster and more accurate results than any other phagocytosis assay. pHrodo® Green conjugates are non-fluorescent outside the cell at neutral pH, but fluoresce brightly green at acidic pH such as in phagosomes. Get faster staining and more accurate results—without the need for wash steps or quencher dye.

• Specific detection of phagocytosis and endocytosis
• Reduced signal variability and improved timing in sensitive experiments
• Enough to do 100 tests when using 100 µL in each well of 96-well plate
• Multiplex with other compatible dyes, such as red florescent protein, TMRM, NucBlue™ Hoechst, and CellROX® Deep Red

The fluorescence of the novel pHrodo® Green dye dramatically increases as pH decreases from neutral to acidic, making it an ideal tool to study phagocytosis and its regulation by drugs and/or environmental factors. The lack of fluorescence outside the cell eliminates the need for wash steps and quencher dyes.

Use the ready-made pHrodo® Green E. coli BioParticles® Conjugate in imaging, high content screening, high throughput screening, and flow applications. pHrodo® Green dye is also available as a conjugate of zymosan BioParticles®, S. aureus BioParticles®, or dextran 10,000 MW. To create other conjugates, such as antibody conjugates, use pHrodo® Green STP ester or pHrodo® Green maleimide.

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

Zymosan A S. cerevisiae BioParticles™, Texas Red™ conjugate (Invitrogen™)

The Molecular Probes® BioParticles® product line consists of a series of fluorescently labeled, heat- or chemically killed bacteria and yeast in a variety of sizes, shapes, and natural antigenicities. These fluorescent BioParticles® products have been employed to study phagocytosis by fluorescence microscopy, quantitative spectrofluorometry, and flow cytometry.

We offer E. coli (K-12 strain), S. aureus (Wood strain, without protein A) and zymosan (S. cerevisiae) BioParticles® conjugates covalently labeled with a variety of different fluorophores (special care has been taken to remove free dye after conjugation). Unlike the fluorescence of fluorescein-labeled BioParticles® conjugates, which is partially quenched in acidic environments, the fluorescence of the Alexa Fluor®, BODIPY® FL, tetramethylrhodamine and Texas Red® dye conjugates is uniformly intense over the pH range from 3 to 10.

BioParticles Specifications:
• Label (Ex/Em): Texas Red® (~595/615 nm)
• Particle: Zymosan (S. cerevisiae)
Opsonizing reagent available


Using BioParticles Products
BioParticles® conjugates are provided as lyophilized powders. There are approximately 3 x 108 E. coli or S. aureus particles per mg solid and approximately 2 x 107 zymosan particles per mg solid. BioParticles® conjugates can be reconstituted in the buffer of your choice for use in phagocytosis assays. The fluorescence of BioParticles® conjugates that are bound to the surface of the cell (but not internalized) can be quenched by ethidium bromide, trypan blue, or other quenchers. In addition to cellular applications, fluorescent BioParticles® conjugates may be effective as flow cytometry calibration references when sorting bacteria and yeast mutants. These small particles may also be useful references for light scattering studies because their sizes and shapes differ in characteristic ways.

Find More BioParticles® Products
We offer a large range of dye-labeled and unlabeled E. coli (K-12 strain), S. aureus (Wood strain, without protein A), and zymosan (S. cerevisiae) BioParticles® products. Find out about these products and their applications by reviewing Probes for Following Receptor Binding and Phagocytosis—Section 16.1 in the Molecular Probes® Handbook.

For pH-sensitive endocytosis assays, see our pHrodo™ BioParticles® conjugates.

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

pHrodo™ Red Zymosan Bioparticles™ Conjugate for Phagocytosis (Invitrogen™)

New pH-sensitive pHrodo® Red dye conjugates give faster and more accurate results than any other phagocytosis assay. pHrodo® Red dye conjugates are non-fluorescent outside the cell, but fluoresce brightly red in phagosomes. Get faster staining and more accurate results—without the need for wash steps or quencher dye.

• Specific detection of phagocytosis and endocytosis
• Reduced signal variability and improved timing in sensitive experiments
• Multiplex with green dyes such as GFP, Fluo-4, or calcein

The fluorescence of the novel pHrodo® Red dye dramatically increases as pH decreases from neutral to acidic, making it an ideal tool to study phagocytosis and its regulation by drugs and/or environmental factors. The lack of fluorescence outside the cell eliminates the need for wash steps and quencher dyes.

Use the ready-made pHrodo® Red Zymosan BioParticles® Conjugate in imaging or flow applications, or pHrodo® Red SE, the activated succinimidyl ester, for labeling microorganisms or proteins of your choice.

In addition, pHrodo® dye is also available in green color, with E. coli, zymosan, S. aureus, and dextran 10,000 conjugates.

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