Shop All Avidin, Streptavidin & Biotin

LanthaScreen™ Tb-Streptavidin, 1 mg/mL Kit

As part of the LanthaScreen® TR-FRET Toolbox of assay reagents, LanthaScreen® Tb-labeled streptavidin is a "generic" reagent that can be used to easily label biotinylated biomolecules with terbium for use in TR-FRET assays. Although the terbium chelate donor can be directly attached to a biomolecule such as a protein or peptide, the Tb-labeled streptavidin can be "indirectly" attached to a target molecule through a biotin-mediated association with Tb-labeled streptavidin.

Streptavidin, Alkaline Phosphatase Conjugate (Invitrogen™)

The streptavidin, alkaline phosphatase conjugate can be used to detect biotin in a signal amplification scheme in conjunction with chromogenic substrates or fluorogenic substrates.

Qdot™ 625 Streptavidin Conjugate (Invitrogen™)

Qdot® 625 Streptavidin Conjugate comprises a biotin-binding protein (streptavidin) covalently attached to a fluorescent label (Qdot® nanocrystal). Streptavidin has a very high binding affinity for biotin, and a conjugate of streptavidin is commonly used together with a conjugate of biotin for specific detection of a variety of proteins, protein motifs, nucleic acids, and other molecules (for example, a biotinylated primary antibody bound to a protein target can be detected with a fluorescently labeled streptavidin). Strategies similar to this are used in many detection protocols including western blots, flow cytometry, imaging and microscopy, and microplate assays, and are also used in purification workflows to achieve targeted fractionation. Qdot® nanocrystal conjugates are provided as 1 µM solutions.

Important Features of Qdot® Streptavidin Conjugates:

• Streptavidin Qdot® 625 conjugate has emission maxima of ~625 nm
• Approximately 5 to 10 streptavidins per Qdot® nanocrystal
• Extremely photostable and bright fluorescence
• Efficiently excited with single-line excitation sources
• Narrow emission, large Stokes shift
• Available in multiple colors
• Ideal for western blots, flow cytometry, imaging and microscopy, microplate assays and more

Properties of Qdot® Nanocrystals
The Qdot® streptavidin conjugate is the size of a large macromolecule or protein (~15–20 nm) and represents the brightest class of streptavidin detection reagents. Qdot® streptavidin conjugates are made from a nanometer-scale crystal of a semiconductor material (CdSe), which is coated with an additional semiconductor shell (ZnS) to improve the optical properties of the material. The Qdot® 705 and Qdot® 800 streptavidin conjugates, which include CdSeTe, are made in a similar fashion. This core-shell material is further coated with a polymer shell that allows the materials to be conjugated to biological molecules and to retain their optical properties.

Other Fluorescent Conjugates of Streptavidin are Available
We offer several other Qdot® colors or try the Qdot® Streptavidin Sampler Kit, containing Qdot® streptavidin conjugates in six colors 525, 565, 585, 605, 655, and 705. In addition to nanocrystal conjugates, we offer a wide range of streptavidins conjugated to Alexa Fluor® dyes, Oregon Green® dye, enzyme conjugates, and traditional fluorophores like Texas Red® dye, fluorescein (FITC) and more.

Find Biotinylated Conjugates
We offer an extensive line of biotinylated conjugates for use in biotin-streptavidin detection strategies.

• Use the primary antibody search tool to find biotinylated primary antibodies
• Use the secondary antibody selector tool to find biotinylated secondary antibodies and biotinylated anti-dye and anti-hapten antibodies

Blocking Endogenous Biotin
Naturally occurring biotins can interfere with biotin-streptavidin detection schemes. For experiments involving fixed and permeabilized cells, try our Endogenous Biotin-Blocking Kit to minimize this interference.

Related Links:
Learn more about Avidin-Biotin Detection
Learn more about Qdot® Nanocrystals

pHrodo™ Red Avidin (Fluorogenic pH Sensor) (Invitrogen™)

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.

Reference:

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

Streptavidin, Alexa Fluor™ 568 conjugate (Invitrogen™)

Alexa Fluor® 568 streptavidin comprises a biotin-binding protein (streptavidin) covalently attached to a fluorescent label (Alexa Fluor® dye). Streptavidin has a very high binding affinity for biotin, and a conjugate of streptavidin is commonly used together with a conjugate of biotin for specific detection of a variety of proteins, protein motifs, nucleic acids, and other molecules (for example, a biotinylated primary antibody bound to a protein target can be detected with a fluorescently labeled streptavidin). Strategies similar to this are used in many detection protocols including western blots, flow cytometry, imaging and microscopy, and microplate assays. Alexa Fluor® dye streptavidin conjugates are supplied as 1 mg lyophilized product or in 0.5 mL volumes of a 2 mg/mL solution.

Important Features of Alexa Fluor® 568 Streptavidin Conjugates:
Alexa Fluor® 568 streptavidin conjugate has Ex/Em maxima of ~ (578/603)
Bright, photostable fluorescence
High solubility in aqueous solutions
Available in multiple colors
Ideal for western blots, flow cytometry, imaging and microscopy, microplate assays and more

Properties of Alexa Fluor® Dyes
Alexa Fluor® dyes are organic fluorescent dyes developed for better performance in imaging and other labeling protocols and exhibit improved photostability and brightness and improved solubility in aqueous solutions. Available in a broad range of colors, these dyes are a good choice for most imaging applications.

Blocking Endogenous Biotin
Naturally occurring biotins can interfere with biotin-streptavidin detection schemes. For experiments involving fixed and permeabilized cells, try our Endogenous Biotin-Blocking Kit to minimize this interference.

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

Related Links:

Learn more about Avidin-Biotin Detection

Learn more about Alexa Fluor® Dyes

Find out about other Labeled Streptavidin Conjugates

Read Avidin and Streptavidin Conjugates-Section 7.6 in the Molecular Probes Handbook

Avidin, Alexa Fluor™ 488 conjugate (Invitrogen™)

Our avidin, Alexa Fluor® 488 conjugate is a bright, photostable probe with excitation and emission characteristics similar to those of fluorescein. Avidin is a glycosylated biotin-binding protein that has a basic isoelectric point and is widely used to detect biotinylated probes.

Streptavidin, (Cy3) (Invitrogen™)

Class: RUO
Statement: For research use only. Not for use in diagnostic procedures.
Buffer: PBS
Preservative: 0.1% Sodium Azide

View a selection guide for all Alexa Fluor® streptavidin and avidin conjugates.

eBioscience™ Streptavidin Super Bright 702 Conjugate (Invitrogen™)

eBioscience Streptavidin Super Bright 702 is a streptavidin-fluorochrome conjugate for indirect staining protocols to detect biotinylated primary antibodies in flow cytometry. Super Bright dyes are polymer-based fluorophores that are excited by the violet laser (405 nm) and emit fluorescence at the wavelength indicated in their name. They are optimized for use in flow cytometry and allow for use of additional channels with violet excitation. Super Bright dyes are fully compatible with other commonly used fluorescent molecules, eBioscience buffers and fixatives, viability stains, and reagents.

Super Bright 702 is a tandem dye that can be excited with the violet laser line (405 nm) and emits at 702 nm. We recommend using a 710/50 bandpass filter or equivalent. Please make sure that your instrument is capable of detecting this fluorochrome.

Applications tested
Streptavidin Super Bright 702 Conjugate has been tested by flow cytometric analysis to detect biotinylated primary antibodies. The amount of this conjugate that will stain a cell sample in a final volume of 100 μL is less than or equal to 0.125 μg. Cell number should be determined empirically but can range from 105 to 108 cells/test. It is recommended that the streptavidin be carefully titrated for optimal performance in the assay of interest.

Samples can be stored in IC Fixation Buffer or 1-step Fix/Lyse Solution for up to three days in the dark at 4°C with minimal impact on brightness and FRET efficiency/compensation. Clone specific performance after fixation should be determined empirically.

When using two or more Super Bright dye-conjugated antibodies in a staining panel, it is recommended to use Super Bright Complete Staining Buffer to minimize any non-specific polymer interactions. Please refer to the datasheet for Super Bright Complete Staining Buffer for more information.

Super Bright polymer dyes are sold under license from Becton, Dickinson and Company.

Streptavidin, Texas Red™-X conjugate (Invitrogen™)

The streptavidin, Texas Red®-X conjugate has excitation and emission maxima ~595/615 and is widely used to detect biotinylated probes by fluorescence microscopy.

eBioscience™ Streptavidin eFluor™ 450 Conjugate (Invitrogen™)

The streptavidin fluorochrome conjugates are commonly used in indirect staining protocols to detect biotinylated primary antibodies in flow cytometry. Streptavidin binds to biotin with high affinity.

Laser
Violet Laser

Emit
445 nm

Excite
405 nm

Reported Application
Flow Cytometric Analysis

Streptavidin Protein, HRP (Thermo Scientific™)

Thermo Scientific™ Pierce™ Streptavidin, Horseradish Peroxidase Conjugate includes streptavidin in a purified form conjugated to peroxidase for substrate-based detection.

Streptavidin, Horseradish Peroxidase Conjugate enables detection of biotinylated antibodies and other probes in a variety of standard assay methods, including western blotting, ELISA, immunohistochemistry, and fluorescence imaging. Streptavidin, Horseradish Peroxidase conjugate is supplied as lyophilized powder in phosphate-based buffer for immediate reconstitution with water.

Streptavidin is a biotin-binding protein originally isolated from Streptomyces avidinii. In contrast to avidin, streptavidin has no carbohydrate and has a mildly acidic pI of 5. Pierce streptavidin products use a recombinant form of streptavidin having a mass of 53,000 daltons and a near-neutral pI. Streptavidin is a tetrameric protein, with each subunit binding one molecule of biotin with affinity similar to that of avidin. Guanidinium chloride will dissociate avidin and streptavidin into subunits, but streptavidin is more resistant to dissociation.

Recommended for use in ELISA (0.1 µg/mL), immunohistochemistry (1-10 µg/mL), and western blot (2 µg/mL) applications.

Related products
Pierce™ Streptavidin
Pierce™ Streptavidin, Alkaline Phosphatase Conjugated
Pierce™ Streptavidin, Maleimide-Activated
Pierce™ Streptavidin, Hydrazide-Activated

Avidin, FITC conjugate (Invitrogen™)

Reactivity: FITC-Avidin reacts with biotin.

Streptavidin, Unconjugated (Invitrogen™)

Purified from Streptomyces avidinii and provided in lyophilized form. The streptavidin/avidin-biotin staining and detection strategy is used when increased assay sensitivity is desired for a wide variety of systems.

Format/Formulation: Unconjugated

Streptavidin, (R-PE) (Invitrogen™)

Class: RUO
Statement: For research use only. Not for use in diagnostic procedures.
Buffer: PBS
Preservative: 0.1% Sodium Azide

View a selection guide for all streptavidin RPE, APC, and tandem conjugates.

Qdot™ 585 Streptavidin Conjugate (Invitrogen™)

Qdot® 585 streptavidin conjugate comprises a biotin-binding protein (streptavidin) covalently attached to a fluorescent label (Qdot® nanocrystal). Streptavidin has a very high binding affinity for biotin, and a conjugate of streptavidin is commonly used together with a conjugate of biotin for specific detection of a variety of proteins, protein motifs, nucleic acids, and other molecules (for example, a biotinylated primary antibody bound to a protein target can be detected with a fluorescently labeled streptavidin). Strategies similar to this are used in many detection protocols including western blots, flow cytometry, imaging and microscopy, and microplate assays, and are also used in purification workflows to achieve targeted fractionation. Qdot® nanocrystal conjugates are provided as 1 µM solutions.

Important Features of Qdot® Streptavidin Conjugates:
Streptavidin Qdot® 585 conjugate has emission maxima of ~585 nm
Approximately 5 to 10 streptavidins per Qdot® nanocrystal
Extremely photostable and bright fluorescence
Efficiently excited with single-line excitation sources
Narrow emission, large Stokes shift
Available in multiple colors
Ideal for western blots, flow cytometry, imaging and microscopy, microplate assays and more

Properties of Qdot® Nanocrystals
The Qdot® streptavidin conjugate is the size of a large macromolecule or protein (~15–20 nm) and represents the brightest class of streptavidin detection reagents. Qdot® streptavidin conjugates are made from a nanometer-scale crystal of a semiconductor material (CdSe), which is coated with an additional semiconductor shell (ZnS) to improve the optical properties of the material. The Qdot® 705 and Qdot® 800 streptavidin conjugates, which include CdSeTe, are made in a similar fashion. This core-shell material is further coated with a polymer shell that allows the materials to be conjugated to biological molecules and to retain their optical properties.

Other Fluorescent Conjugates of Streptavidin are Available
We offer several other Qdot® colors or try the Qdot® Streptavidin Sampler Kit, containing Qdot® streptavidin conjugates in six colors 525, 565, 585, 605, 655, and 705. In addition to nanocrystal conjugates, we offer a wide range of streptavidins conjugated to Alexa Fluor® dyes, Oregon Green® dye, enzyme conjugates, and traditional fluorophores like Texas Red® dye, fluorescein (FITC) and more.

Find Biotinylated Conjugates
We offer an extensive line of biotinylated conjugates for use in biotin-streptavidin detection strategies.
• Use the primary antibody search tool to find biotinylated primary antibodies
• Use the secondary antibody selector tool to find biotinylated secondary antibodies and biotinylated anti-dye and anti-hapten antibodies

Blocking Endogenous Biotin
Naturally occurring biotins can interfere with biotin-streptavidin detection schemes. For experiments involving fixed and permeabilized cells, try our Endogenous Biotin-Blocking Kit to minimize this interference.

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

Related Links:

Learn more about Avidin-Biotin Detection

To learn more about Qdot® Nanocrystals