Dynabeads™ M-270 Streptavidin, for OEM and industrial use only - FAQs

View additional product information for Dynabeads™ M-270 Streptavidin, for OEM and industrial use only - FAQs (35302)

10 product FAQs found

I am getting high background using Dynabeads M-280 Streptavidin magnetic beads. How can I prevent this from happening?

The background might be caused by nonspecific binding to the BSA on the bead surface. Alternatively, high background might be caused by nonspecific binding to streptavidin. Increasing either the pH or the salt concentration might help reduce the binding. Dynabeads M-270 Streptavidin magnetic beads might be a better alternative; these beads are not coated with BSA and are hydrophilic, as they are based upon carboxylic acid chemistry.

What is the binding capacity of streptavidin-coupled Dynabeads magnetic beads?

- One milligram of Dynabeads M-280 Streptavidin magnetic beads typically binds 650-900 pmol of free biotin, 200 pmol of biotinylated peptide, up to 10 µg of biotinylated antibody, 10 µg of biotinylated double-stranded DNA, or 200 pmol of biotinylated single-stranded oligonucleotides.

- One milligram of Dynabeads M-270 Streptavidin magnetic beads typically binds more than 950 pmol of free biotin, 200 pmol of biotinylated peptide, up to 10 µg of biotinylated antibody, 10 µg of biotinylated double- stranded DNA, or 200 pmol of biotinylated single-stranded oligonucleotides.

- One milligram of Dynabeads MyOne Streptavidin C1 magnetic beads typically binds more than 2,500 pmol free biotin, 400 pmol of biotinylated peptides, up to 20 µg of biotinylated antibody, 20 µg of biotinylated double-stranded DNA, or 500 pmol of biotinylated single-stranded oligonucleotides.

-One milligram of Dynabeads MyOne Streptavidin T1 magnetic beads typically binds 1,100-1,700 pmol free biotin, 400 pmol of biotinylated peptides, up to 20 µg of biotinylated antibody, 20 µg of biotinylated double- stranded DNA, or 400 pmol of biotinylated single-stranded oligonucleotides.

Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.

For how long can the Streptavidin-coupled Dynabeads magnetic beads be stored?

Storage should be at 2 to 8 degrees C. Freezing or drying of the Dynabeads magnetic beads is not recommended. Provided the Dynabeads magnetic beads are stored correctly, quality is guaranteed until the expiry date stated on the label.

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How may I optimize binding capacity of streptavidin-coupled Dynabeads magnetic beads?

The binding capacity of streptavidin-coupled Dynabeads magnetic beads is fragment length-dependent. Reduced binding capacity for large DNA fragments may be due to steric hindrance. For large DNA fragments (greater than 2 kb in size), we recommend using Dynabeads kilobaseBINDER Kit.

-Salt concentration affects the binding efficiency of biotinylated nucleic acids to the Streptavidin-coupled Dynabeads magnetic beads. Optimal binding conditions for biotinylated DNA fragments (up to 1 kb) are achieved at 1 M NaCl (final concentration), 25 degrees C and 15 min incubation time. Longer DNA fragments should be immobilized overnight. Biotinylated antibodies should be immobilized in PBS buffer pH 7.4, supplemented with 0.1% BSA.

-Ensure that your sample does not contain an excess of free biotin, as the free biotin will bind Streptavidin-coupled Dynabeads magnetic beads much more rapidly than larger biotinylated molecules. Biotinylated oligonucleotides should be recovered by reverse phase HPLC or FPLC to remove free biotin from the sample.

-We also recommend a titration to optimize the quantity of beads used for each individual application, since both the size of the specific molecule to be immobilized and the biotinylation procedures affect the binding capacity of the beads.

Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.

I have used biotinylated antibodies coupled to Dynabeads Streptavidin magnetic beads for immunoprecipitation (IP). How do I elute my target protein from the antibody without eluting the antibody off the beads?

Use mild elution conditions, e.g., a buffer with high salt or low pH. Heating the beads at 95 degrees C for 5 mins in SDS sample buffer will elute the antibody as well.

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How can I dissociate my biotinylated molecule from Dynabeads Streptavidin magnetic beads?

The streptavidin-biotin interaction is the strongest known non-covalent biological interaction between a protein and a ligand. Binding of biotin and streptavidin is very rapid and, once formed, the complex is unaffected by wide extremes of pH, temperature, organic solvents, and other denaturing agents. Normally, very harsh methods are required to dissociate the biotin from streptavidin, which will be irreversibly denatured by the procedure. Biotin-streptavidin interactions are more easily reversible when biotin derivatives with lower binding affinity are used along with chemically modified streptavidins with lower biotin binding affinity. When modified biotins and streptavidins are used, gentle methods for inducing reversible binding are available

To dissociate biotinylated proteins from streptavidin, boil the beads in 0.1% SDS or SDS-PAGE buffer for 3 mins or incubate them in 8 M guanidinium hydrochloride, pH 1.5.

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Can Dynabeads Streptvidin magnetic beads be boiled?

We do not recommend this because streptavidin becomes hydrophobic and aggregates during heat-induced denaturation.

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Which Dynabeads Streptavidin magnetic beads should I use for my application?

The product to choose depends on the properties of your sample, the buffers and solutions you will use, as well as your downstream application. In general, all the Dynabeads Streptavidin beads can be used in applications involving biotinylated ligands. However, some beads may perform better than the others in particular applications due to their characteristics. Please refer to the Dynabeads Streptavidin Selection Guide (https://www.thermofisher.com/us/en/home/brands/product-brand/dynal/streptavidin-coupled-dynabeads.html#selection) for detailed information.

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Can streptavidin become detached from the surface of Dynabeads Streptavidin Beads?

The streptavidin molecule is covalently attached to the surface of the beads; under normal, recommended conditions, negligible leakage is detected (less than 0.2% of total attached streptavidin after 2 months at 37 degrees C). However, it should be noted that not all of the four streptavidin subunits are covalently coupled to the beads. Typically, one or two of the subunits are covalently coupled. Streptavidin is like other proteins; if heated, it can denature and dissociate into subunits. If Dynabeads Streptavidin magnetic beads are, for instance, boiled, some of the streptavidin subunits may be released (as monomers or aggregates) from the beads. The covalently bound streptavidin subunits will not be affected by such treatment. When streptavidin is bound to biotin, the streptavidin-biotin complex is more stable than the unbound streptavidin molecule

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How many streptavidin molecules are on Dynabeads Streptavidin Beads?

The exact number of streptavidin molecules bound per bead is not measured, but is approximately 14-16 µg streptavidin per mg Dynabeads M-280 Streptavidin magnetic beads.

Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.