• USA Home
  • S4762 - Streptavidin from Streptomyces avidinii

S4762 Sigma

Streptavidin from Streptomyces avidinii

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



Related Categories Antibodies, Biotin/Avidin, Molecular Biology, Plant Biotechnology, Plant Proteomics,
form   essentially salt-free, lyophilized powder
mol wt   mol wt ~60 kDa
capacity   4 mol/mol (Biotin)
Featured Industry   Research Pathology
storage temp.   −20°C



5, 10 mg in glass bottle

Package size based on protein content.

Preparation Note

Affinity purified.

General description

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 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.

Price and Availability

LC-MS Grade Solvents and Reagents

Explore with Confidence

Celebrate Pi Day!
Safety & Documentation

Safety Information

NONH for all modes of transport
WGK Germany 


Certificate of Analysis

Certificate of Origin

Frequently Asked Questions

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. These documents are located on the product detail page under Useful Links & Tools. Click on the following link to search for a Certificate of Analysis. Please click the following link to see the details on our Product Dating Information.
How do I get lot-specific information or a Certificate of Analysis?
A Certificate of Analysis is available by lot number and can be obtained through our Advanced Search Option: http://www.sigmaaldrich.com/catalog/AdvancedSearchPage.do
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. 
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, or search here. 
My question is not addressed here, how can I contact Technical Service for assistance?
Use the option to the right to "Ask a Question" by email of a Technical Service Scientist.
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.
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.
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.
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).
Show more questions
Protocols & Articles


Antibody Basics

Immunoglobulins (Igs) are produced by B lymphocytes and secreted into plasma. The Ig molecule in monomeric form is a glycoprotein with a molecular weight of approximately 150 kDa that is shaped more ...
Keywords: Affinity chromatography, Centrifugation, Chromatography, Digestions, Direct immunofluorescence, Gene expression, High performance liquid chromatography, Immunofluorescence, Ion Exchange, Microscopy, Precipitation, Purification, Rheumatology, Scanning electron microscopy

Related Content

Antibody Explorer | Buy Primary & Secondary Antibodies

Monoclonal and polyclonal primary antibodies are focused on cell biology, neurobiology and molecular biology. Secondary antibodies targeting multiple host’s IgG are conjugated to alkaline phosphatase...
Keywords: Amplification, Buffers, Cell biology, Enzyme-linked immunosorbent assay, Immunofluorescence, Immunohistochemistry, Inflammation, Molecular biology, Phosphorylations, Purification, Western blot

Peer-Reviewed Papers


Related Products

related product

Product #


Add to Cart

92210 Timestrip Plus 0 °C
06693 Timestrip Plus -20 °C

Technical Service:

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

Bulk Ordering & Pricing:

Need larger quantities for your development, manufacturing or research applications?