Shop All Avidin, Streptavidin & Biotin

Streptavidin Protein, DyLight 633 (Invitrogen™)

Streptavidin for Western Blot, IF, ICC, IHC, IP, ELISA

Qdot™ 605 Streptavidin Conjugate (Invitrogen™)

Qdot® 605 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® 605 conjugate has emission maxima of ~605 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

eBioscience™ Streptavidin PE-Cyanine5 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
Blue Laser, Green Laser, Yellow-Green Laser

Emit
667 nm

Excite
488 - 561 nm

Reported Application
Flow Cytometric Analysis

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.

NeutrAvidin Protein, AP (Thermo Scientific™)

Thermo Scientific™ alkaline phosphatase-conjugated NeutrAvidin Protein is a specially-prepared form of avidin that decreases background in biotin-binding.

Features include:
Near-neutral isoelectric point—pI = 6.3, more neutral than native avidin
Nearly devoid of glycosylation—decreased possibility of lectin binding compared to native avidin
No RYD recognition sequence—no known off-target binding domains like streptavidin
Affordable—significantly less expensive than streptavidin

NeutrAvidin Protein is deglycosylated native avidin from egg whites. Removal of the excess carbohydrate by an exclusive process yields a protein with a more neutral isoelectric point and less nonspecific binding properties. Conjugated NeutrAvidin Protein provides exceptional performance in western blot, ELISA, and IHC applications that require biotin-binding probes. Assay specificity, sensitivity, and signal-to-noise ratios with NeutrAvidin Protein are generally equivalent or better than with the significantly more expensive streptavidin.

Avidin is a glycoprotein found in the egg white and tissues of birds, reptiles, and amphibia. The biotin-binding protein contains four identical subunits having a combined mass of 67,000-68,000 daltons. Removing the glycosylation from avidin yields NeutrAvidin Protein with a mass of 60,000 daltons. Carbohydrate-based lectin binding is reduced to undetectable levels, yet biotin-binding affinity is retained. NeutrAvidin Protein offers the advantages of a neutral pI to minimize nonspecific adsorption, along with lysine residues that remain available for derivatization or other customized conjugation. NeutrAvidin Protein yields the lowest nonspecific binding among the known biotin-binding proteins. The specific activity for biotin binding is approximately 14 µg/mg of protein, which is near the theoretical maximum activity.

Applications:
In situ hybridization—NeutrAvidin-AP Conjugate is currently being used by the Allen Institute for Brain Science to create the Allen Brain Atlas.
Western blotting—use NeutrAvidin Protein conjugates (HRP or AP) instead of streptavidin conjugates for detection of biotinylated target proteins or biotinylated primary or secondary antibodies in western blots.
ELISA—NeutrAvidin Protein conjugates (HRP or AP) replace corresponding streptavidin conjugates for direct or indirect sandwich ELISA detection schemes involving biotin-labeled proteins and antibodies. Depending on the specific assay components (e.g., blocking buffers, etc.), NeutrAvidin Protein conjugates provide similar or better assay performance measured as signal-to-noise ratio.

Related products
NeutrAvidin™ Protein
NeutrAvidin™ Protein, Horseradish Peroxidase Conjugated
NeutrAvidin™ Protein, Fluorescein Conjugated
NeutrAvidin™ Protein, Maleimide-Activated

Streptavidin-CY3 (ZyMax Grade) (Invitrogen™)

Applications: Immunohistochemistry, Western blotting, ELISA, ISH

ZyMAX™ reagents offer enhanced assay sensitivity, higher titer, and greater flexibility in assay design than standard grade reagents.

Qdot™ 525 ITK™ Streptavidin Conjugate Kit (Invitrogen™)

The Qdot® 525 ITK™ Streptavidin Conjugate Kit provides the Qdot® streptavidin conjugate as 250 µL of a 2 µM solution. Unlike the Qdot® streptavidin conjugates, the Qdot® ITK™ streptavidin conjugates have the streptavidin covalently attached to the inner amphiphilic coating without a PEG linker. These Qdo® conjugates can be used for binding biotinylated probes. The kit also includes 30 mL of Qdot® incubation buffer.

Avidin, AP conjugate (Invitrogen™)

Reactivity: AP-Avidin reacts with biotin.

Applications: Immunohistochemistry, ELISA

Avidin Protein, HRP (Invitrogen™)

Avidin for Western Blot, IHC, ELISA

Streptavidin, (FITC) (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.

Streptavidin Protein, DyLight 680 (Invitrogen™)

Streptavidin for Western Blot, IF, ICC, IHC, IP, ELISA

eBioscience™ Streptavidin PerCP-eFluor™ 710 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
Blue Laser

Emit
710 nm

Excite
488 nm

Reported Application
Flow Cytometric Analysis

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

NeutrAvidin Protein (Thermo Scientific™)

Thermo Scientific™ NeutrAvidin Protein is a specially-prepared form of avidin that decreases background in biotin-binding.

Features include:
Near-neutral isoelectric point—pI = 6.3, more neutral than native avidin
Nearly devoid of glycosylation—decreased possibility of lectin binding compared to native avidin
No RYD recognition sequence—no known off-target binding domains like streptavidin
Affordable—significantly less expensive than streptavidin

NeutrAvidin Protein is deglycosylated native avidin from egg whites. Removal of the excess carbohydrate by an exclusive process yields a protein with a more neutral isoelectric point and less nonspecific binding properties. Purified NeutrAvidin Protein provides exceptional performance in western blot, ELISA, and IHC applications that require biotin-binding probes. Assay specificity, sensitivity, and signal-to-noise ratios with NeutrAvidin Protein are generally equivalent or better than with the significantly more expensive streptavidin.

Avidin is a glycoprotein found in the egg white and tissues of birds, reptiles, and amphibia. The biotin-binding protein contains four identical subunits having a combined mass of 67,000-68,000 daltons. Removing the glycosylation from avidin yields NeutrAvidin Protein with a mass of 60,000 daltons. Carbohydrate-based lectin binding is reduced to undetectable levels, yet biotin-binding affinity is retained. NeutrAvidin Protein offers the advantages of a neutral pI to minimize nonspecific adsorption, along with lysine residues that remain available for derivatization or other customized conjugation. NeutrAvidin Protein yields the lowest nonspecific binding among the known biotin-binding proteins. The specific activity for biotin binding is approximately 14 µg/mg of protein, which is near the theoretical maximum activity.

Related products
NeutrAvidin™ Protein, Horseradish Peroxidase Conjugated
NeutrAvidin™ Protein, Alkaline Phosphatase Conjugated
NeutrAvidin™ Protein, Fluorescein Conjugated
NeutrAvidin™ Protein, Maleimide-Activated

Streptavidin Protein, APC (Invitrogen™)

Streptavidin for Western Blot, ELISA

Avidin, FITC conjugate (Invitrogen™)

Our avidin, fluorescein conjugate has excitation and emission maxima ~494/518. Avidin is a glycosylated biotin-binding protein that has a basic isoelectric point and is widely used to detect biotinylated probes.

Streptavidin, Alexa Fluor™ 594 Conjugate (Invitrogen™)

Alexa Fluor® 594 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® 594 Streptavidin Conjugates:
Alexa Fluor® 594 streptavidin conjugate has Ex/Em maxima of ~ (590/617)
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

Streptavidin Protein, FITC (Invitrogen™)

Streptavidin for Western Blot, IF, ELISA

Qdot™ 525 Streptavidin Conjugate (Invitrogen™)

Qdot® 525 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® 525 conjugate has emission maxima of ~525 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
To learn more about Qdot® Nanocrystals

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

Streptavidin-Horseradish Peroxidase (HRP) Conjugate (Invitrogen™)

Streptavidin-HRP conjugate is typically used in the immunodetection of biotinylated proteins. This conjugate is suitable for use in immunoblotting, ELISA, immunomicroscopy. The amount of conjugate provided is sufficient for 25 western blots using 10 ml of working solution per reaction or 25 immunostaining reactions using 1 ml of working solution per reaction as appropriate.

Streptavidin, Pacific Blue™ conjugate (Invitrogen™)

Our streptavidin, Pacific Blue™ conjugate is a bright, blue-fluorescent probe with excitation/emission ~410/455 nm. Streptavidin is a nonglycosylated biotin-binding protein that is isolated from bacteria and has a near-neutral isoelectric point. It is widely used to detect biotinylated probes, because it reportedly exhibits less nonspecific binding than does the glycosylated, biotin-binding protein, avidin.

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

Streptavidin Protein, DyLight 405 (Invitrogen™)

Streptavidin for Western Blot, IF, ICC, IHC, IP, ELISA

Streptavidin, Alexa Fluor™ 546 conjugate (Invitrogen™)

Alexa Fluor® 546 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® 546 Streptavidin Conjugates:
Alexa Fluor® 546 streptavidin conjugate has Ex/Em maxima of ~ (556/573)
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

NeutrAvidin Protein, FITC (Invitrogen™)

NeutrAvidin for Western Blot, IHC, ELISA, ISH

Streptavidin, Alexa Fluor™ 610—R-Phycoerythrin Conjugate (Alexa Fluor™ 610—R-Phycoerythrin Streptavidin) (Invitrogen™)

The streptavidin, Alexa Fluor™ 610-R-phycoerythrin streptavidin tandem conjugate has excitation and emission maxima at ~496,565/627 and is widely used to detect biotinylated probes by flow cytometry. Not only are the Alexa Fluor™ 610 conjugates of R-PE are more fluorescent than the commercially available Texas Red™ conjugates of R-PE, the fluorescent emission of Alexa Fluor™ 610-R-PE tandem conjugates is shifted to somewhat longer wavelengths than is the emission of Texas Red™-R-PE conjjgates, resulting in better separation from the emission of R-PE.

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

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

Qdot™ 800 ITK™ Streptavidin Conjugate Kit (Invitrogen™)

The Qdot® 800 ITK™ Streptavidin Conjugate Kit provides the Qdot® streptavidin conjugate as 250 µL of a 2 µM solution. Unlike the Qdot® streptavidin conjugates, the Qdot® ITK™ streptavidin conjugates have the streptavidin covalently attached to the inner amphiphilic coating without a PEG linker. These Qdo® conjugates can be used for binding biotinylated probes. The kit also includes 30 mL of Qdot® incubation buffer.

Qdot™ 705 Streptavidin Conjugate (Invitrogen™)

Qdot® 705 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® 705 conjugate has emission maxima of ~705 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
To learn more about Qdot® Nanocrystals

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

Avidin, NeutrAvidin™, Texas Red™ conjugate (Invitrogen™)

Our Texas Red® conjugate of NeutrAvidin® biotin-binding protein - a form of avidin that has been processed to remove carbohydrate and to lower its isoelectric point - can substantially decrease background due to nonspecific binding. The method used to deglycosylate the avidin retains its specific binding. This bright, red-fluorescent reagent (absorption/emission maxima ~595/615 is ideal for detecting biotinylated targets in fluorescence microscopy applications.

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

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.

eBioscience™ Streptavidin eFluor™ 615 Conjugate (Invitrogen™)

The streptavidin fluorochrome conjugates are commonly used in indirect staining protocols to detect biotinylated primary antibodies in immunohistochemistry and immunocytochemistry applications. Streptavidin binds to biotin with high affinity.

Emit
615 nm

Excite
595 nm

Reported Application
Immunocytochemistry, Immunohistochemical Staining of Frozen Tissue Sections, Immunohistochemical Staining of Formalin-Fixed Paraffin Embedded Tissue Sections

Streptavidin, Alexa Fluor™ 633 conjugate (Invitrogen™)

Alexa Fluor® 633 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® 633 Streptavidin Conjugates:
Alexa Fluor® 633 streptavidin conjugate has Ex/Em maxima of ~ (632/647)
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

Streptavidin - Cy3 (Invitrogen™)

Reactivity: CY3-SA reacts with biotin.

Qdot™ 605 ITK™ Streptavidin Conjugate Kit (Invitrogen™)

The Qdot® 605 ITK™ Streptavidin Conjugate Kit provides the Qdot® streptavidin conjugate as 250 µL of a 2 µM solution. Unlike the Qdot® streptavidin conjugates, the Qdot® ITK™ streptavidin conjugates have the streptavidin covalently attached to the inner amphiphilic coating without a PEG linker. These Qdo® conjugates can be used for binding biotinylated probes. The kit also includes 30 mL of Qdot® incubation buffer.

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.

Pierce™ High Sensitivity NeutrAvidin™-HRP (Thermo Scientific™)

Thermo Scientific Pierce High Sensitivity NeutrAvidin HRP Conjugate is a specially prepared peroxidase-conjugated form of avidin biotin-binding protein that provides signal amplification like poly-HRP and exceptional storage stability.

Features of High Sensitivity NeutrAvidin HRP Conjugate:

NeutrAvidin Protein—a specially deglycosylated form of avidin that provides highly specific, low-background binding of biotinylated antibodies in many applications.
High sensitivity—detect low levels of target without background; obtain high signal-to-noise ratios
Cost effective—use less conjugate in Western blotting and ELISA applications and still obtain excellent results
Flexible—compatible with typical chemiluminescent, fluorescent and colorimetric peroxidase substrates
Convenient—ready-to-use stabilized liquid format means there is no waiting for thawing and no need to aliquot

This specially-manufactured variety of HRP-conjugated avidin protein meets the demands of today's scientists for more sensitive detection in ELISA and Western blotting applications. The conjugate is suitable for use with chemiluminescent, chemifluorescent or colorimetric substrates. Each High Sensitivity HRP conjugate is packaged in an easy-to-use stabilized solution that enables convenient storage at 4°C for at least one year.

Our High Sensitivity HRP Conjugates outperform the competition on target detection, signal intensity and signal-to-noise ratios. For example, experiments indicate that the High Sensitivity Streptavidin-HRP can be diluted eight-to 10-fold more than traditional HRP conjugates and still produce similar results.

Pierce™ Avidin, Fluorescein (FITC) Conjugated (Thermo Scientific™)

Thermo Scientific Pierce FITC Conjugated Avidin is a purified avidin protein from hen egg whites that effectively binds biotin, a tag that is frequently used to tag antibodies and other probes for immunodetection methods.

Features of Pierce Avidin:

Native avidin—glycoprotein from chicken egg whites, 67kDa, pI = 10
Soluble—glycosylation and isoelectric point renders avidin more soluble than streptavidin
Affordable—significantly less expensive than recombinant streptavidin
ABC staining—avidin is usually preferred over streptavidin for avidin-biotin complex (ABC) staining methods in immunohistochemistry (IHC)
Pure protein—choose pure, unconjugated avidin for use in ABC staining

Avidin is a glycoprotein found in the egg white and tissues of birds, reptiles and amphibia. This protein contains four identical subunits having a combined molecular mass of 67,000 to 68,000 daltons. Each subunit binds one molecule of biotin, and studies have shown that tryptophan and lysine are involved in the binding site for biotin. The sequencing of the subunit indicates it consists of 128 amino acids. Avidin has an isoelectric point of 10-10.5 and is very soluble in water and salt solutions. Avidin is stable over a wide range of pH values and temperatures. Extensive chemical modification has little effect on the activity of avidin, making it useful for detection and protein purification.

Related Products
Pierce™ Avidin
Pierce™ Avidin, Horseradish Peroxidase Conjugated

Streptavidin, Alexa Fluor™ 635 conjugate (Invitrogen™)

Far-red fluorescent Alexa Fluor 635 streptavidin has absorption/emission maxima of ~633/647 nm. Streptavidin is a nonglycosylated biotin-binding protein that is isolated from bacteria and has a near-neutral isoelectric point. It is widely used to detect biotinylated probes, because it reportedly exhibits less nonspecific binding than does the glycosylated, biotin-binding protein, avidin.

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

Streptavidin, Alexa Fluor™ 700 conjugate (Invitrogen™)

Alexa Fluor® 700 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® 700 Streptavidin Conjugates:
Alexa Fluor® 700 streptavidin conjugate has Ex/Em maxima of ~ (702/723)
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

eBioscience™ Streptavidin eFluor™ 506 Conjugate (Invitrogen™)

eBioscience Streptavidin eFluor 506 is a streptavidin-fluorochrome conjugate for indirect staining protocols to detect biotinylated primary antibodies in flow cytometry. eFluor organic dyes are traditional fluorescent dyes for use in multiple applications, including multicolor flow cytometry and immunofluorescence microscopy. To make fluorophore selection easier, all eFluor organic dyes are named after their emission wavelength, and they are fully compatible with most conventional dyes, fluorescent molecules, eBioscience buffers and fixatives, viability stains, and reagents.

The eFluor 506 organic dye is a violet-laser excitable fluorophore that has an emission peak of 506 nm. This dye is optimized for use in flow cytometry and, when combined with all five Super Bright dye antibody conjugates, can provide six detection channels of the violet laser. We recommend using a 510/20 band pass filter or equivalent. Please make sure that your instrument is capable of detecting this fluorochrome.

Applications tested
Streptavidin eFluor 506 Conjugate has been tested by flow cytometric analysis to detect biotinylated primary antibodies. It can be used ≤ 0.125 μg per test. A test is defined as the amount (μg) of streptavidin fluorochrome conjugate that will stain a cell sample in a final volume of 100 μL. 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.

Alexa Fluor™ 488 Streptavidin, 10 nm colloidal gold conjugate (Invitrogen™)

Alexa Fluor® 488 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® 488 Streptavidin Conjugates:
Alexa Fluor® 488 streptavidin conjugate has Ex/Em maxima of ~ (495/519)
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

Streptavidin, Alexa Fluor™ 430 conjugate (Invitrogen™)

Our Alexa Fluor 430 streptavidin conjugate is a bright, green-fluorescent probe (absorption/emission maxima ~434/539 nm). Streptavidin, a nonglycosylated biotin-binding protein with a near-neutral isoelectric point, reportedly exhibits less nonspecific binding than avidin.

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

Streptavidin, Alexa Fluor™ 514 conjugate (Invitrogen™)

Alexa Fluor® 514 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® 514 Streptavidin Conjugates:
Alexa Fluor® 514 streptavidin conjugate has Ex/Em maxima of ~ (518/540)
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

Streptavidin - Agarose (Invitrogen™)

Reactivity: SA-Seph 4B reacts with biotin.

NeutrAvidin Protein, DyLight 550 (Invitrogen™)

NeutrAvidin for IF

Avidin, NeutrAvidin™, PE conjugate (Invitrogen™)

Our R-phycoerythrin (R-PE) conjugate of NeutrAvidin® biotin-binding protein - a form of avidin that has been processed to remove carbohydrate and to lower its isoelectric point - can substantially decrease background due to nonspecific binding. The method used to deglycosylate the avidin retains its specific binding. This bright, fluorescent reagent is ideal for detecting biotinylated targets in flow cytometry applications.

eBioscience™ Streptavidin Super Bright 436 Conjugate (Invitrogen™)

eBioscience Streptavidin Super Bright 436 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 436 can be excited with the violet laser line (405 nm) and emits at 436 nm. We recommend using a 450/50 bandpass filter or equivalent. Please make sure that your instrument is capable of detecting this fluorochrome.

Applications tested
Streptavidin Super Bright 436 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.

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 Protein, DyLight 800 (Invitrogen™)

Streptavidin for Western Blot, IF, ICC, IHC, IP, ELISA

Pierce™ High Sensitivity Streptavidin-HRP, Pre-Diluted (Thermo Scientific™)

Thermo Scientific Pierce High Sensitivity Streptavidin-HRP, 2 mL is an exclusive peroxidase-conjugated streptavidin biotin-binding protein that provides signal amplification like poly-HRP and exceptional storage stability.

Features of High Sensitivity Streptavidin-HRP, 2 mL:

High sensitivity—detect low levels of target without background; obtain high signal-to-noise ratios
Cost effective—use less conjugate in Western blotting and ELISA applications and still obtain excellent results
Flexible—compatible with typical chemiluminescent, fluorescent and colorimetric peroxidase substrates
Convenient—ready-to-use stabilized liquid format means there is no waiting for thawing and no need to aliquot

This specially-manufactured variety of HRP-conjugated streptavidin protein meets the demands of today's scientists for more sensitive detection in ELISA and Western blotting applications. The conjugate is suitable for use with chemiluminescent, chemifluorescent or colorimetric substrates. Each High Sensitivity HRP conjugate is packaged in an easy-to-use stabilized solution that enables convenient storage at 4°C for at least one year.

Our High Sensitivity HRP Conjugates outperform the competition on target detection, signal intensity and signal-to-noise ratios. Experiments indicate that the High Sensitivity Streptavidin-HRP can be diluted 8-to 10-fold more than traditional HRP conjugates and still produce similar results.

Related Products
Pierce™ High Sensitivity Streptavidin-HRP

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.

Ultra Streptavidin-HRP (Thermo Scientific™)

Streptavidin-HRP consists of streptavidin protein that is covalently conjugated to horseradish peroxidase (HRP) enzyme. Streptavidin binds to biotin and the conjugated HRP provides a high level of activity for detection using an appropriate substrate system.

Features of Streptavidin-HRP:

Product Number: N504
Size: 1.5 mL
Formulation: Conjugate in stabilizer solution containing protein and preserved with 0.02% methyliso-thiazolone, 0.02% bromonitrodioxane, and 0.002% other active isothiazolones.
Storage: Shipped on cold packs. Store at 2-8°C. Stable until expiration date if stored under these conditions.
Application: ELISA: to be used with biotin-labeled detection antibodies. Recommended dilution range is 1:400 - 1:2,000 in ELISA diluent (e.g., PBS containing 4% protease-free BSA) . The optimal dilution must be determined empirically for each specific application. Prepare dilutions immediately before use.

Pierce™ Avidin (Thermo Scientific™)

Thermo Scientific Pierce Avidin is a purified avidin protein from hen egg whites that effectively binds biotin, a tag that is frequently used to tag antibodies and other probes for immunodetection methods.

Features of Pierce Avidin:

Native avidin—glycoprotein from chicken egg whites, 67kDa, pI = 10
Soluble—glycosylation and isoelectric point renders avidin more soluble than streptavidin
Affordable—significantly less expensive than recombinant streptavidin
ABC staining—avidin is usually preferred over streptavidin for avidin-biotin complex (ABC) staining methods in immunohistochemistry (IHC)
Pure protein—choose pure, unconjugated avidin for use in ABC staining

Avidin is a glycoprotein found in the egg white and tissues of birds, reptiles and amphibia. This protein contains four identical subunits having a combined molecular mass of 67,000 to 68,000 daltons. Each subunit binds one molecule of biotin, and studies have shown that tryptophan and lysine are involved in the binding site for biotin. The sequencing of the subunit indicates it consists of 128 amino acids. Avidin has an isoelectric point of 10-10.5 and is very soluble in water and salt solutions. Avidin is stable over a wide range of pH values and temperatures. Extensive chemical modification has little effect on the activity of avidin, making it useful for detection and protein purification.

Related Products
Pierce™ Avidin, Horseradish Peroxidase Conjugated
Pierce™ Avidin, Fluorescein (FITC) Conjugated

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

The streptavidin, Rhodamine-Red™-X conjugate has excitation and emission maxima ~570/590 and is widely used to detect biotinylated probes by fluorescence microscopy.

Avidin, NeutrAvidin™, Oregon Green™ 488 conjugate (Invitrogen™)

Our Oregon Green® 488 conjugate of NeutrAvidin® biotin-binding protein - a form of avidin that has been processed to remove carbohydrate and to lower its isoelectric point - can substantially decrease background due to nonspecific binding. The method used to deglycosylate the avidin retains its specific binding. This bright, green-fluorescent reagent (absorption/emission maxima ~496/524 nm) is ideal for detecting biotinylated targets in fluorescence microscopy and flow cytometry applications.

Streptavidin HRP (ELISA GD) (Invitrogen™)

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

Format/Formulation: HRP Conjugate (ELISA grade)

Streptavidin, Alexa Fluor™ 680 Conjugate (Invitrogen™)

Alexa Fluor® 680 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® 680 Streptavidin Conjugates:
Alexa Fluor® 680 streptavidin conjugate has Ex/Em maxima of ~ (679/702)
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

eBioscience™ Streptavidin PE 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
Blue Laser, Green Laser, Yellow-Green Laser

Emit
578 nm

Excite
488 - 561 nm

Reported Application
Flow Cytometric Analysis

NeutrAvidin Protein, DyLight 633 (Invitrogen™)

NeutrAvidin for Western Blot, IF, ICC, IHC, IP, ELISA

NeutrAvidin Protein, HRP (Thermo Scientific™)

Thermo Scientific™ NeutrAvidin Protein-HRP is a specially-prepared form of avidin that decreases background in biotin-binding conjugated to peroxidase for substrate based detection.

Features include:
Near-neutral isoelectric point—pI = 6.3, more neutral than native avidin
Nearly devoid of glycosylation—decreased possibility of lectin binding compared to native avidin
No RYD recognition sequence—no known off-target binding domains like streptavidin
Affordable—significantly less expensive than streptavidin

NeutrAvidin Protein is deglycosylated native avidin from egg whites. Removal of the excess carbohydrate by an exclusive process yields a protein with a more neutral isoelectric point and less nonspecific binding properties. Purified and conjugated forms of NeutrAvidin Protein provide exceptional performance in western blot, ELISA, and IHC applications that require biotin-binding probes. Assay specificity, sensitivity, and signal-to-noise ratios with NeutrAvidin Protein are generally equivalent or better than with the significantly more expensive streptavidin.

Avidin is a glycoprotein found in the egg white and tissues of birds, reptiles, and amphibia. The biotin-binding protein contains four identical subunits having a combined mass of 67,000-68,000 daltons. Removing the glycosylation from avidin yields NeutrAvidin Protein with a mass of 60,000 daltons. Carbohydrate-based lectin binding is reduced to undetectable levels, yet biotin-binding affinity is retained. NeutrAvidin Protein offers the advantages of a neutral pI to minimize nonspecific adsorption, along with lysine residues that remain available for derivatization or other customized conjugation. NeutrAvidin Protein yields the lowest nonspecific binding among the known biotin-binding proteins. The specific activity for biotin binding is approximately 14µg/mg of protein, which is near the theoretical maximum activity.

Recommended applications: ELISA (assay dependent), immunohistochemistry (assay dependent), in situ hybridization (ISH) (assay dependent), western blot (assay dependent)