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Streptavidin from Streptomyces avidinii

essentially salt-free, lyophilized powder, ≥13 units/mg protein

CAS Number:
MDL number:

Quality Level


essentially salt-free, lyophilized powder

specific activity

≥13 units/mg protein

mol wt

~60 kDa


4 mol/mol (Biotin)


research pathology

storage temp.


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General description

Streptavidin is a crystalline protein isolated from the bacterium Streptomyces avidinii and possesses biotin-binding ability. It has four binding sites for biotin like avidin and binds four molecules of biotin. Streptavidin is now considered as a new type of biotin-binding protein.
Streptavidin derives its name from its bacterial source Streptomyces avidinii and from the hen egg-white protein, avidin, which has high affinity to biotin. Its homologous core shares 33% sequence similarity with avidin, as well as sharing a common tetrameric structure. It is a crystalline tetrameric protein, with a molecular weight of 4*15000Da. It binds four molecules of biotin. Streptavidin lacks carbohydrate and sulfur-containing amino acids.


Streptavidin from Streptomyces avidinii has been used:
  • in wire functionalization
  • in streptavidin capture enzyme-linked immunosorbent assay (ELISA)
  • in microbubble preparation


5, 10 mg in glass bottle

Preparation Note

Affinity purified.


Unless otherwise stated in our catalog or other company documentation accompanying the product(s), our products are intended for research use only and are not to be used for any other purpose, which includes but is not limited to, unauthorized commercial uses, in vitro diagnostic uses, ex vivo or in vivo therapeutic uses or any type of consumption or application to humans or animals.

Storage Class Code

13 - Non Combustible Solids



Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

Certificate of Analysis

Enter Lot Number to search for Certificate of Analysis (COA).

Certificate of Origin

Enter Lot Number to search for Certificate of Origin (COO).

Product Information Sheet

Quotes and Ordering

  1. Which document(s) contains shelf-life or expiration date information for a given product?

    If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis.

  2. How do I get lot-specific information or a Certificate of Analysis?

    The lot specific COA document can be found by entering the lot number above under the "Documents" section.

  3. How do I find price and availability?

    There are several ways to find pricing and availability for our products. Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote.  USA customers:  1-800-325-3010 or view local office numbers.

  4. What is the Department of Transportation shipping information for this product?

    Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product. 

  5. In what is Product No. S4762 soluble? And how do you recommend storing solutions of streptavidin?

    This product is soluble in water or aqueous buffer (i.e., PBS) at 1 mg/mL. Solutions in PBS or water can be stored for several months at 4°C, or for more than a year as frozen aliquots.

  6. How do I determine how many units are in a particular amount of Product No. S4762?

    On the Certificate of Analysis for the product, the activity of the product per milligram can be found. This number is specific for your lot, and you must look up the Certificate of Analysis by the lot number for your particular batch of product. From this number, you can calculate how many units are in a particular weight of your product by multiplying the weight of the product by the units/mg of the product.

  7. What is the expiration date of the Product No. S4762 in my possession?

    Product No. S4762 has not been assigned an expiration date by Sigma. Streptavidin is stable. S4762 has been assigned a QC Release date as well was a Retest Date. These dates can be found on the Certificate of Analysis. The QC Release Date indicates the last date that the lot was tested and found to meet specifications, and the Retest Date indicates the next date that the lot will be tested, assuming that enough of the lot remains to perform the testing.

  8. What is the affinity of streptavidin (e.g., Product No. S4762) for biotin?

    Streptavidin binds the small molecule biotin with extraordinary affinity. The dissociation constant is KD = 4 × 10-14 M, according to N. M. Green, Methods Enzymol., 184, 51 (1990).

  9. My question is not addressed here, how can I contact Technical Service for assistance?

    Ask a Scientist here.

Viability of endothelial cells after ultrasound-mediated sonoporation: Influence of targeting, oscillation, and displacement of microbubbles
van R T, et al.
Journal of Controlled Release : Official Journal of the Controlled Release Society, 238, 197-211 (2016)
Biotinylated CdSe/ZnSe nanocrystals for specific fluorescent labeling.
Charvet N et al
Journal of Materials Chemistry, 14.17 , 2638-2642 (2004)
A rapid streptavidin-capture ELISA specific for the detection of antibodies to feline foamy virus.
Winkler IG et al
Journal of Immunological Methods, 207(1), 69-77 (1997)
Timo Vögtle et al.
eLife, 8 (2019-08-23)
The immunoreceptor tyrosine-based inhibition motif (ITIM)-containing receptor G6b-B is critical for platelet production and activation. Loss of G6b-B results in severe macrothrombocytopenia, myelofibrosis and aberrant platelet function in mice and humans. Using a combination of immunohistochemistry, affinity chromatography and proteomics
Mapping of functional domains in the p22(phox) subunit of flavocytochrome b(559) participating in the assembly of the NADPH oxidase complex by "peptide walking".
Dahan I et al
The Journal of Biological Chemistry, 277(10), 8421-8432 (2002)

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

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