Thermo Scientific NeutrAvidin Protein is a specially-prepared form of avidin that decreases background in for biotin-binding and is available in purified form, as enzyme and fluor conjugates, and activated for sulfhydryl conjugation.
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.
Highlights:
- 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
- Available in multiple formats – choose purified NeutrAvidin Protein, prepared HRP and AP conjugates or activated forms for a variety of techniques.
Product Details:
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.
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Comparison of available Thermo Scientific Biotin-Binding Proteins.
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Avidin
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Streptavidin
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NeutrAvidin Protein
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Molecular Weight
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67K
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53K
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60K
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Biotin-binding Sites
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4
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4
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4
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Isoelectric Point (pI)
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10
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6.8-7.5
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6.3
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Specificity
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Low
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High
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Highest
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Affinity for Biotin (Kd)
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10-15 M
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10-15 M
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10-15 M
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Nonspecific Binding
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High
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Low
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Lowest
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Applications:
- 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.
- Immunohistochemistry – try NeutrAvidin Protein in place of avidin in customized IHC detection systems, including signal-amplification methods like the avidin-biotin complex (ABC) technique. Depending on other assay components, decreased background and lower limits of detection may be possible.
- In Situ Hybridization – NeutrAvidin-AP Conjugate is currently being used by the Allen Institute for Brain Science to create the Allen Brain Atlas.
References:
- Hiller, et al. (1987). Biochem. J. 248, 167-171.
- Brett, P.J., et al.(200). J. Biol. Chem. 277, 20468-20476
- Unson, M.D. et al. (1999) J. Clin. Microbiol. 37 2153-2157.
- Wojciechoski, M., et al (1999) Clin.Chem. 45 1690-1693.
- Glover, B.P. and McHenry, C.S. (2001) Cell 105, 925-934.
- Guo, Y., et al (2001). J. Biol. Chem. 276, 45791-45799.
- Claypool, S.M., et al.(2002). J. Biol. Chem. 277(31) 28038-28050.
Related Resources:
Protein Methods Library: Immunodetection strategies for IHC
Related Products:
High Sensitivity NeutrAvidin-HRP – conjugates with "poly-HRP" sensitivity
DyLight Fluor NeutrAvidin Conjugates – complete line of high-performance fluorescent conjugates
NeutrAvidin Protein Agarose and UltraLink Resins – high-capacity biotin-binding affinity beads
NeutrAvidin Coated Microplates – for biotin-based capture assays
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