Dynabeads™ MyOne™ Streptavidin T1

We do not recommend this as streptavidin becomes hydrophobic and aggregates during denaturation.

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.

Please review the following possibilities for why your Dynabeads magnetic beads are not pelleting:

- The solution is too viscous.
- The beads have formed aggregates because of protein-protein interaction.

Try these suggestions: - Increase separation time (leave tub on magnet for 2-5 minutes)
- Add DNase I to the lysate (~0.01 mg/mL)
- Increase the Tween 20 concentration to ~0.05% of the binding and/or washing buffer.
- Add up to 20 mM beta-merecaptoethanol to the binding and/or wash buffers.

Find additional tips, troubleshooting help, and resources within our Dynabeads Nucleic Acid Purification Support Center.

Which product to choose depends on the properties of your sample, the buffers and solutions applied, as well as the downstream application. In general, all Dynabeads Streptavidin beads can be used in applications involving biotinylated ligands; however, some beads may perform better than others in particular applications due to their characteristics. Dynabeads M-280 Streptavidin beads and Dynabeads MyOne Streptavidin T1 beads are commonly used for protein and nucleic acid applications. Dynabeads M-270 Streptavidin beads and MyOne Streptavidin C1 beads are preferred for nucleic acid diagnostics, specifically with samples that have a high concentration of chaotropic salts, immunoassays involving small biotinylated antigens, and in applications that are not compatible with BSA, as these beads are not blocked with BSA. Dynabeads MyOne Streptavidin beads offer increased binding capacity and slower sedimentation rate, making them ideal for automated applications and when larger amounts of a biotinylated compound or its specific target need to be isolated. Please see the selection guide here ( https://www.thermofisher.com/us/en/home/brands/product-brand/dynal/streptavidin-coupled-dynabeads.html?icid=fr-strep-1).

You can assay the supernatant for unbound nucleic acid to determine the amount of nucleic acid bound to the Dynabeads Streptavidin beads. The concentration of nucleic acids can be checked by measuring the OD or by running them on a gel. Alternatively, the nucleic acids can be labeled radioactively and the concentration measured directly on the beads, or fluorescently and measured in the supernatant.