Invitrogen™ Dynabeads™ Streptavidin Magnetic Beads

Catalog No.	Product Type	Quantity
65-001	Dynabeads™ MyOne™ Streptavidin C1	2 mL
65-002	Dynabeads™ MyOne™ Streptavidin C1	10 mL
65-604-D	Dynabeads™ MyOne™ Streptavidin T1	50 mL
65-602	Dynabeads™ MyOne™ Streptavidin T1	10 mL
65-601	Dynabeads™ MyOne™ Streptavidin T1	2 mL
65605D	Dynabeads™ Streptavidin for Target Enrichment	2 mL
65606D	Dynabeads™ Streptavidin for Target Enrichment	10 mL
65607D	Dynabeads™ Streptavidin for Target Enrichment	50 mL
11-205-D	Dynabeads™ M-280 Streptavidin	2 mL
11-206-D	Dynabeads™ M-280 Streptavidin	10 mL
60-210	Dynabeads™ M-280 Streptavidin	100 mL
65-305	Dynabeads™ M-270 Streptavidin	2 mL
65-306	Dynabeads™ M-270 Streptavidin	10 mL
60-101	Dynabeads™ kilobaseBINDER™ Kit	200 Isolations
65-801-D	Dynabeads™ Streptavidin Trial Kit	4 x 1 mL

Catalog No. 65-001 Supplier Invitrogen™ Supplier No. 65001

Description

Includes

Supplied in PBS, pH 7.4 with 0.1% BSA and 0.02% NaN₃ added as preservatives.

Dynabeads Streptavidin Magnetic Beads are designed for high-specificity, low-background capture of target molecules with biotinylated affinity binders such as antibodies, antigens, or oligonucleotides. Available in various sizes and surface chemistries, these beads can be tailored to provide the best fit for specific application needs.

Dynabeads Streptavidin Magnetic Beads are designed for high-specificity, low-background capture of target molecules with biotinylated affinity binders such as antibodies, antigens, or oligonucleotides. Available in various sizes and surface chemistries, these beads can be tailored to provide the best fit for specific application needs.

Dynabeads Streptavidin Magnetic Beads are compatible with high-throughput automation platforms, including KingFisher sample purification systems, ensuring seamless integration into new and existing workflows.

Key advantages of Dynabeads Streptavidin Magnetic Beads

• ISO 13485–certified manufacturing—exceptional manufacturing control to ensure robust and consistent performance between production lots, meeting international quality standards for medical devices
• Monosized, monodispersed magnetic beads—uniform particle size provides consistent and reproducible results across applications
• Dual size options—available in 1-μm and 2.8-μm diameter specifications to accommodate diverse experimental requirements and application-specific needs
• Multiple surface chemistry options—various surface functionalization chemistries available to optimize binding efficiency and compatibility for specific applications
• Application-optimized design—size and surface chemistry combinations enable best-fit selection for targeted experimental protocols and assay requirements

Precision-engineered manufacturing delivers exceptional control over critical bead properties

Dynabeads Streptavidin products are based on magnetic polystyrene-based beads that are covalently coupled with recombinant streptavidin, creating a robust platform for target capture and isolation using biotinylated affinity binders. Dynabeads Streptavidin product manufacturing enables exceptional precision over three critical parameters: size distribution, magnetization properties, and surface chemical characteristics. This ensures consistent performance across batches and applications, providing the reliability necessary for reproducible experimental outcomes.

Optimized size selection enhances application-specific performance

The Dynabeads Streptavidin product line offers two distinct size options, each engineered to excel in specific experimental contexts. The 1-μm beads, available in the Dynabeads MyOne series, are ideally suited for applications requiring fast reaction kinetics, slow sedimentation rates, and high sensitivity-to-capacity ratios. These smaller beads provide enhanced surface area contact and reduced gravitational settling, making them particularly valuable for sensitive detection assays.

In contrast, the 2.8-μm beads, found in the Dynabeads M-270 and M-280 series, are perfect for applications demanding low background binding and reduced risk of aggregation in aggregation-prone applications. These larger beads offer even easier handling and faster magnetic separation compared to the Dynabeads MyOne series, facilitating streamlined workflow processing.

Tailored surface chemistry options address diverse experimental requirements

The Dynabeads Streptavidin product line includes two distinct surface chemistry configurations designed to optimize performance across varied experimental conditions. Hydrophobic surfaces are available in Dynabeads MyOne Streptavidin T1, Dynabeads Streptavidin for Target Enrichment, and Dynabeads M-280 Streptavidin products. These surfaces are BSA-blocked after streptavidin coupling making them ideal for high signal-to-noise applications such as immunoassays, target enrichment, and on-bead PCR for next-generation sequencing.

Alternatively, hydrophilic surfaces are featured in Dynabeads MyOne Streptavidin C1, Dynabeads Streptavidin for In Vitro Transcription, and Dynabeads M-270 Streptavidin products. These surfaces contain no BSA blocking and are particularly suitable for hydrophobic targets, harsh lysis conditions, sample preparation workflows for mass spectrometry, and applications demanding low or no nuclease activity, such as on-bead reverse transcription or in vitro transcription.

For researchers uncertain about which bead type best suits their application, a Dynabeads Streptavidin Trial Kit is available. It allows for side-by-side performance evaluation of different bead formulations under your specific experimental conditions, ensuring optimal selection for your research needs.

ISO 13485 certification ensures scalable quality and OEM support

Manufactured under ISO 13485 certification, Dynabeads Streptavidin products deliver outstanding batch-to-batch consistency. This robust quality assurance framework ensures that once customers develop an assay or workflow, they can rely on reproducible results across multiple experimental iterations. This consistency makes these versatile beads an efficient solution for applications spanning the entire spectrum from fundamental research to commercial manufacturing processes. For researchers developing commercial products or services, or those requiring larger bulk volumes, specialized support is available by emailing oemdynal@thermofisher.com.

Order Info

Shipping Condition: Room Temperature

Specifications

• Bead Type: Magnetic polystyrene-based beads covalently coupled with recombinant Streptavidin
• Concentration: 10 mg/mL
• Content And Storage: Dynabeads MyOne Streptavidin C1 are supplied in PBS, pH 7.4, with 0.01% Tween-20 and 0.09% NaN₃. Store at 2–8°C.
  
  
• Format: Beads in Suspension
• Isolation Technology: Magnetic Bead
• Diameter (Metric): 1 μm (CV < 5%)
• For Use With (Equipment): KingFisher™ Sample Purification System, DynaMag™ magnets
• For Use With (Application): Immunoassays, immunoprecipitations, or viral DNA/RNA and mRNA isolations for downstream nucleic acid amplification workflows, requiring high sensitivity, capacity, or rapid target capture, under harsh conditions or minimal nuclease activity
• High-throughput Compatibility: High-throughput Compatible
• Product Line: Dynabeads
• Product Type: Dynabeads™ MyOne™ Streptavidin C1
• Quantity: 2 mL
• Shipping Condition: Ambient Temperature
• Binding Property: ≥2800 pmol free biotin/mg beads
• Regulatory Status: For Research Use Only
• Certifications/Compliance: ISO9001 and ISO13485
• Surface Functionality: Carboxylic acid hydrophilic surface, non-blocked

Frequently Asked Questions (FAQs)

Can Dynabeads Streptavidin magnetic beads be boiled?

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

Which streptavidin-conjugated Dynabeads magnetic beads are the right beads for my application?

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).

How do I measure the binding of biotinylated nucleic acid on streptavidin beads?

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.

Can Dynabeads Streptavidin beads be used directly in PCR or real-time PCR reactions?

Our Dynabeads Streptavidin magnetic beads can be used directly in PCR or real-time PCR. However, you would have to empirically optimize the amount of beads to be used per volume of reaction.

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 milligram Dynabeads M-280 Streptavidin magnetic beads.

Is a spacer arm required on the ligand when doing biotinylation?

All biotin reagents should contain a spacer arm, at least a 6-carbon linker, to reduce steric hindrance. This is because the bicyclic ring of biotin goes deep into the biotin binding cleft in streptavidin. A 6-carbon arm is the minimum length between biotin and the first base of sequence that is required to reduce the steric hindrance effect. The longer this distance is, the less the steric hindrance. A 6-carbon linker is standard linker size from most companies and should be enough for most applications. We recommend specific biotinylation at the 5'-end of the probe.

What is the difference between direct and indirect capture?

In direct capture, the biotinylated probe/ligand is first coupled to the Dynabeads magnetic beads followed by addition of your sample. In indirect capture, the biotinylated probe/ligand is first added to the sample followed by addition of your Dynabeads magnetic beads. Precoupled ligand for direct capture allows you to reuse the Dynabeads magnetic beads, while an indirect approach can be beneficial when the concentration of your target is low, specific affinity is weak, or the binding kinetics is slow. Please see the following link (https://www.thermofisher.com/us/en/home/life-science/dna-rna-purification-analysis/napamisc/capture-of-biotinylated-targets/nucleic-acid-capture-assays.html) for a diagram of the capture.

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.

What is the optimal pH to reduce the settling rate for Dynabeads magnetic beads?

This is dependent on coating or the biotinylated molecule properties. Our recommendation is that this should be tested to find optimum conditions for the specific assay.

What is the density of Dynabeads magnetic beads?

The density of Dynabeads magnetic beads is a challenging property to determine. The reason is that Dynabeads magnetic beads have a 17-37% magnetic iron oxide content in order to have a reasonable magnetic separation time, and the density of the iron oxide is about 4.9 g/cm³. Dynabeads magnetic beads are composite materials, being a mix of polymers and iron oxide, and there are very few polymers that have a density below 1.

The sedimentation rate depends on the bead diameter squared, so the sedimentation of a 1 µm bead is much slower than that of 2.8 µm. The effect of diameter on sedimentation rate is to some extent counteracted by the fact that smaller beads need to have a higher content of iron oxide for magnetic separation applications. Typically, our M-280 Dynabeads (diameter 2.8 µm) have a density of 1.4 g DS/cm³ (DS = dry substance), our M-270 Dynabeads (diameter 2.8 µm) and M-450 Dynabeads (diameter 4.5 µm) have a density of 1.6 g DS/cm³, and our MyOne Dynabeads (diameter 1 µm) have a density of 1.8 g DS/cm³. as well as our Dynabeads Cell Isolation and Expansion Support Center and Protein Immunoprecipitation (IP), Co-Immunoprecipitation (Co-IP), and Pulldown Support Center.

Which methods are common for dissociation of the nonbiotinylated strand of Dynabeads Streptavidin magnetic beads from the biotinylated one?

Several methods can be used.

Using heat:
Wash the DNA-coated Dynabeads magnetic beads in 50µL 1x SSC. (To make SSC, dissolve 0.15 M NaCl, 0.015 M sodium citrate in 800 mL water. Adjust pH to 7.0 with NaOH. Adjust the volume to 1 L with water.)

Resuspend the beads in another 50µL of 1x SSC.

Incubate at 95 degrees C for 5 min.

Quickly put the tube in a magnet stand for 1-2 min and transfer the supernatant to a new tube. The supernatant contains the nonbiotinylated DNA strand.

Generally, heat destabilizes the interaction between biotin and streptavidin and can increase the release of biotinylated ligands from streptavidin. This effect varies in different reagents. In water, normally this effect is minimal, especially if it contains salt.

Using NaOH:< br />
Wash the DNA-coated Dynabeads magnetic beads in 50µL 1 x SSC.

Resuspend the beads in 20 µl of freshly prepared 0.15 M NaOH.

Incubate at room temperature for 10 min.

Put the tube in a magnet stand for 1-2 min and transfer the supernatant to a new tube. The supernatant contains the nonbiotinylated DNA strand.

Neutralize the probe by adding 2.2µL 10 x TE, pH 7.5, and 1.3µL 1.25 M acetic acid. The Dynabeads magnetic beads coated with a biotinylated DNA strand can be washed once with 50µL 0.1 M NaOH, once with 50µL of Binding and Wash buffer, and once with 50µL TE buffer.

In general, which probe length is better, considering the binding capacity and specificity?

A probe length between 20 and 50 bases is generally okay. The capacity, measured as number of targets captured, is determined by the length of the targets and not as much by the density of probes on the surface.

Which of the Dynabeads Streptavidin magnetic beads should I choose if binding capacity is key?

If binding capacity is of importance, Dynabeads MyOne Streptavidin C1 magnetic beads is a good choice.

Will washing in water affect the biotin-streptavidin bond to Dynabeads Streptavidin magnetic beads?

After biotinylated DNA has been bound to Dynabeads Streptavidin magnetic beads, the complex can be washed in water without influencing the streptavidin or the binding.

How can I reduce non-specific binding of nucleic acids to Dynabeads MyOne streptavidin magnetic beads and Dynabeads M-270 Streptavidin magnetic beads?

Maintaining a high pH will maintain the negative charge on both the nucleic acid and the beads. So, we recommend keeping the pH high in combination with a low salt concentration. Additionally, to reduce the non-specific binding or high background, we recommend blocking the beads with BSA or BSA + Tween-20.

How can the nonbiotinylated strand be eluted from Dynabeads Streptavidin magnetic beads?

Separation of two DNA strands can be done by treating with either alkali or high temperature.

Using alkali, the nonbiotinylated strand can be eluted with 0.1 M NaOH. This treatment should normally not have any affect on the beads.

Wash the Dynabeads-DNA complex once in 2x Binding and Wash buffer prior to NaOH treatment and remove the supernatant. The high salt concentration will help to reduce the charge and hence minimize nonspecific binding.

Add freshly made (this is critical) 0.1 M NaOH to the Dynabeads-DNA complex and incubate at room temperature for 2-3 min (maximum 5 min) with rotation. Remove the supernatant containing the nonbiotinylated strand.

Wash the Dynabeads-DNA complex once more with 0.1 M NaOH and remove the supernatant. Most of the nonbiotinylated DNA will come off during the first elution.

Heating at 95 degrees C for 5 min in water is an alternative to the alkali treatment. This requires fast separation to prevent reannealing, preferably on ice. Please note that heating will cause some percentage of biotinylated DNA to be dissociated from streptavidin. Therefore, we usually recommend alkali treatment.

How can I estimate binding capacity to Dynabeads Streptavidin magnetic beads?

Biotinylated and radioactively labelled antibodies can be used to estimate binding capacity.

Can Dynabeads Streptavidin magnetic beads be reused?

We do not recommend to re-use the Dynabeads since we can not be sure if the functional groups or the background have been removed. However, if the Dynabeads Streptavidin magnetic beads have been used in applications such as isolation of DNA binding proteins or hybridization capture of specific DNA sequences, the beads with immobilized probe may be reused up to ten times. However, for most applications, it is not possible to reuse the beads. The streptavidin-biotin bond is one of the strongest biological bonds known, and the conditions necessary to break this bond also destroy the streptavidin molecules.

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

The beads should be washed twice, and then stored at 4 degrees C in the buffer they are supplied in. NaN3 can be added to the buffer as a preservative if the beads are to be stored for a longer period. It is also possible to store the beads in TE buffer, pH 8.0.

Can the biotinylated nucleic acid strand be dissociated from Dynabeads Streptavidin magnetic beads?

Breaking the biotin-streptavidin bond requires harsh conditions. For dissociating biotinylated DNA from Dynabeads Streptavidin magnetic beads, we recommend heating in 10 mM EDTA, 95% formamide, pH 8.2, for 5 min at 65 degrees C or for 2 min at 90 degrees C. Alternatively, the Dynabeads-DNA complex may be boiled for 5 min in 0.1% SDS.

Are Dynabeads Streptavidin magnetic beads RNase free?

Dynabeads Streptavidin magnetic beads are not supplied in RNase-free solution. For RNA manipulations, the beads should be washed twice for 1-3 min in a DEPC-treated 0.1 M NaOH, 0.05 M NaCl solution. DEPC is very toxic and is used to get rid of RNases. After washing, the beads can be resuspended in a DEPC-treated 0.1 M NaCl solution. (DEPC treated means adding 0.1% DEPC to the NaCl solution, mixing, incubating for 1 hr at room temperature and autoclaving the DEPC-treated solution to destroy the DEPC).

Will biotinylation inhibit enzymatic activities?

Biotinylation easily inhibits enzymatic activities.

Can streptavidin leak from the streptavidin-coupled Dynabeads?

The streptavidin molecule is covalently attached to the bead's surface. However, not all of the four streptavidin subunits are covalently coupled to the beads, typically only one or two are covalently coupled. Streptavidin is like other proteins; if heated it can denature and dissociate into subunits. If streptavidin-coupled Dynabeads are 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 streptavidin itself. Under normal, recommended conditions, only negligible leakage of streptavidin from the beads is detected (less than 0.2% of total attached streptavidin after 2 months at 37 degrees C).

How many biotin binding sites are on Dynabeads Streptavidin Beads?

Streptavidin is a protein made up of four identical subunits, each containing a high affinity binding site for biotin (KD = 10-15 M). Streptavidin has the same biotin binding properties as avidin, but less nonspecific binding is observed. After immobilization on the beads, there are 2-3 binding sites free for interaction with biotin. as well as ourProtein Immunoprecipitation (IP), Co-Immunoprecipitation (Co-IP), and Pulldown Support Center.

How will Dynabeads Streptavidin Beads behave in Dynabeads KilobaseBINDER Buffer?

The Dynabeads KilobaseBINDER Buffer is a viscous solution and therefore the beads will behave differently in this buffer than in other buffers. Be patient while resuspending the beads in the buffer and try to avoid pumping air into the tube. Flicking the tube containing the beads and buffer must be done very carefully.

If still not completely dissolved, leave it on a roller at 4 degrees C.

What is the supplied concentration of Dynabeads Streptavidin Beads?

Dynabeads M-280 Streptavidin magnetic beads are supplied at 10 mg (approx. 6.7 x 10e8) beads per mL, dissolved in phosphate buffered saline (PBS), pH 7.4, containing 0.1% BSA and 0.02% NaN3 as a preservative.

Dynabeads M-270 Streptavidin magnetic beads are supplied at both 10 mg (approx. 6.7 x 10e8) beads per mL and at 50 mg (approx. 3.2 x 10e9) beads per mL. Both products are dissolved in PBS, pH 7.4, containing 0.02% NaN3 as a preservative.

Dynabeads MyOne Streptavidin C1 magnetic beads are supplied at 10 mg (approx. 7-12 x 10e9) beads per mL, dissolved in PBS, pH 7.4, containing 0.01% Tween 20 detergent and 0.09% NaN3 as a preservative.

Dynabeads MyOne Streptavidin T1 magnetic beads are supplied at 10 mg (approx. 7-12 x 10e9) beads per mL, dissolved in PBS, pH 7.4, containing 0.01% Tween 20 detergent and 0.02% NaN3 as a preservative.

What should I do if Dynabeads Streptavidin magnetic beads aggregate?

Dynabeads M-270 Streptavidin magnetic beads and Dynabeads MyOne C1 magnetic beads have a negatively charged surface. The surface charge of the beads may in some samples cause the beads to float or become sticky or aggregate. The stickiness may be due to electrostatic interactions between the beads or between the beads and the tube wall. Usually we recommend washing the beads in a nonionic detergent like Tween 20 detergent before doing the experiment. The problem is usually reduced or eliminated by simply adding Tween 20 detergent to a final concentration of up to 0.1% to the beads, followed by resuspension and washing in buffer without the detergent. An incubation in the Tween 20 solution may be needed, e.g. 5-10 min at room temperature on a roller. In addition, we recommend using siliconized tubes. This treatment will most likely reduce the electrostatic potential of the beads.

How can I break the streptavidin-biotin interaction?

Breaking the biotin-streptavidin bond requires harsh conditions. For dissociating biotinylated DNA from Dynabeads Streptavidin Beads, heat in 10 mM EDTA, pH 8.2, 95% formamide for 5 min at 65 degrees C or for 2 min at 90 degrees C. Alternatively, the Dynabeads-DNA complex may be boiled for 5 min in 0.1% SDS. Please be aware that these beads cannot be reused after this treatment. as well as our Protein Immunoprecipitation (IP), Co-Immunoprecipitation (Co-IP), and Pulldown Support Center.

What fragment length and capacity can be coupled to Dynabeads Streptavidin magnetic beads?

The capacity is dependent on the fragment size due to steric hindrance. For example, twice as many 500 bp fragments will bind to Dynabeads M-280 Streptavidin magnetic beads than a 1,000 bp fragment. Long DNA fragments will occupy more space around the beads and make it more difficult to "find" the streptavidin on the beads. Smaller fragments will access the streptavidin more easily. For DNA fragments greater than 2 kb, the Dynabeads kilobaseBINDER Kit is recommended. This kit contains Dynabeads M-280 Streptavidin magnetic beads and a special binding solution that enhances immobilization of long (greater than 2 kb) biotinylated DNA fragments. For DNA fragments greater than 1-2 kb, the Dynabeads kilobaseBINDER Kit is recommended, as the binding solution will enhance binding capacity. The binding solution will linearize the DNA so that it stretches out and the bases stack in a rigid structure (it will not work for shorter fragments such as plasmids or circular nucleic acids).

The salt concentration influences the efficiency of binding 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 excess free biotin, as the free biotin will bind Dynabeads Streptavidin Beads much more rapidly than larger molecules. Biotinylated oligonucleotides should be recovered by reverse phase HPLC or FPLC to avoid free biotin from being present in the sample. Titration is performed 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 will affect the binding capacity of the beads.

Can double-stranded DNA be isolated using Dynabeads magnetic beads?

For isolating large fragments of dsDNA, the Dynabeads kilobaseBINDER Kit should have much higher binding capacity (200-600 µg DNA per mg Dynabeads magnetic beads) than the Dynabeads MyOne Streptavidin C1 magnetic beads (~20 µg per mg Dynabeads magnetic beads). The larger the dsDNA, the more advantage the Dynabeads kilobaseBINDER Kit format would have (this is in large part due to the buffer system).

Both of these Dynabeads products have excellent signal:noise ratio, but the 1 µm beads (Dynabeads MyOne Streptavidin C1 magnetic beads) sediment slower so they work better in automated 96-well format. Conversely, the 2.8 µm beads (Dynabeads kilobaseBINDER magnetic beads) are faster to bind to the magnet and easier to manually handle.

Basically, for large total amounts of dsDNA oligos or smaller fragments, for samples with high chaotropic salt concentration, and if you are interested in avoiding BSA, we recommend the Dynabeads MyOne Streptavidin C1 magnetic beads (Cat. No. 65001). For large ds DNA fragments (>4 kb), we recommend the Dynabeads kilobaseBINDER Kit (Cat. No. 60101).

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.

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.

What is the Dynabeads MyOne Streptavidin C1 (Cat. No. 65001) binding capacity for desthiobiotin?

We do not have a specific value in terms in binding capacity of Dynabeads MyOne Streptavidin C1 (Cat. No. 65001) for desthiobiotin. While desthiobiotin can bind to proteins in a 1:1 stoichiometry similar to biotin, which typically binds >2,500 ρmoles free biotin per one mg of beads, it can also form multiple binding interactions, which could lead to higher stoichiometries such as 2:1 or 2:2.

Will the streptavidin-biotin bond be stable in ammonium carbonate buffer at 56 degrees C?

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.

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.

As a negative control, I mixed my uncoated Streptavidin-Coupled Dynabeads with my sample but got lots of non-specific binding to the beads. Why?

When exposed to a sample consisting of different types of molecules, any solid phase matrix can interact with these molecules due to hydrophobicity, charge or other types of interactions. It is not surprising that you get non-specific binding to the beads. This method is actually used for pre-clearing of sample and is not considered a good negative control. When pre-blocked and coated with a specific molecule, beads show a lot less non-specific binding than when they are not coated. As a negative control, you could try beads that are coated with an irrelevant molecule.

I have a dsDNA biotinylated on streptavidin Dynabeads. How can I dissociate the non-biotinylated DNA strand from the biotinylated one?

There are two methods to dissociate the non-biotinylated DNA from the biotinylated DNA strand. The following protocols are based on using 20 µL of Dynabeads Streptavidin, but are scalable. Both methods may release very small amounts of complementary biotinylated strand from streptavidin. If it is critical that no biotinylated strand is released, either adopt a different biotin modification using dual biotin (two biotin groups in sequence) or covalently bind DNA to e.g., Dynabeads M-270 Carboxylic Acid.

Using heat:

- Wash the DNA coated Dynabeads in 50 µL 1 x SSC.*
- Resuspend the beads in another 50 µL of 1 x SSC Incubate at 95 degrees C for 5 mins.
- Quickly put the tube in magnet stand for 1-2 mins and transfer the supernatant to a new tube.
- The supernatant contains your non-biotinylated DNA strand.

Using NaOH:

- Wash the DNA coated Dynabeads in 50 µL 1 x SSC.*
- Resuspend the beads in 20 µl of freshly prepared 0.15 M NaOH.
- Incubate at room temperature for 10 mins. Put the tube in magnet stand for 1-2 mins and transfer the supernatant to a new tube.
- The supernatant contains your non-biotinylated DNA strand. Neutralize the probe by adding 2.2 µL 10 x TE, pH 7.5 and 1.3 µL 1.25 M acetic acid.

Wash the Dynabeads coated with biotinylated strand once with 50 µL 0.1M NaOH, once with 50 µL of B&W buffer and once with 50 µL TE buffer.

*1 x SSC (0.15 M NaCl, 0.015 M sodium citrate. Dissolve the reagents in 800 mL water. Adjust pH to 7.0 with NaOH. Adjust the volume to 1 liter with water).

How do I measure the binding of biotinylated molecules on streptavidin Dynabeads?

Assay the supernatant for unbound molecules. This will determine the amount of molecule bound to the Dynabeads. For nucleic acids, the concentration can be checked by OD readings, or by running a gel. For proteins, the concentration in the supernatant can be determined by a spectrometer using a protein assay like BCA. Alternatively, you can label the molecule with radioactivity or fluorescence and measure the concentration of molecule directly on the beads (former) or in the supernatant (latter).

Which buffers do you recommend using for immobilizing biotinylated molecules?

PBS is the recommended immobilization buffer for biotinylated proteins or other molecules. For immobilization of biotinylated nucleic acids, we recommend the following Binding and Wash (B&W) buffer: 10.0 mM Tris-HCl (pH 7.5) 1.0 mM EDTA 2.0 M NaCl.

How many biotin binding-sites are there per streptavidin molecule?

Streptavidin is a protein composed of four identical subunits, each containing a high affinity binding site for biotin (K-D = 10 -15 M) . Streptavidin has the same biotin binding properties as avidin, but it has a low isoelectric point (pI=5) and no carbohydrate groups, resulting in low non-specific binding.

Which Streptavidin-Coupled Dynabeads are best for my application?

This will depend on the properties of your sample, the buffers and solutions used and your downstream application. For an overview, see Invitrogen Streptavidin-Coupled Dynabeads (https://www.thermofisher.com/us/en/home/brands/product-brand/dynal/streptavidin-coupled-dynabeads.html). In general, they can all be used, but some may perform better than others in particular applications due to their characteristics.
- Invitrogen Dynabeads M-280 Streptavidin (https://www.thermofisher.com/order/catalog/product/11205D#/11205D) and Invitrogen Dynabeads MyOne Streptavidin T1 (https://www.thermofisher.com/order/catalog/product/65601#/65601) are used for both protein and nucleic acids applications.
- Invitrogen Dynabeads M-270 Streptavidin (https://www.thermofisher.com/order/catalog/product/65305#/65305) and Invitrogen Dynabeads MyOne Streptavidin C1 (https://www.thermofisher.com/order/catalog/product/65001#/65001) are preferred for molecular diagnostics and for handling samples with high concentration of chaotropic salt, as well as in immunoassays involving small biotinylated antigens and in applications that are not compatible with BSA as these beads are not blocked with BSA.
- The Dynabeads Streptavidin Trial Kit (https://www.thermofisher.com/order/catalog/product/65801D#/65801D) allows you to try 1 mL of all four (while supplies last).
- The Dynabeads MyOne Streptavidin C1/T1 offer an increased binding capacity and slower sedimentation rate, making them ideal for automated applications and/or for when larger amount of biotinylated molecules or their specific target need to be isolated. as well as our Protein Immunoprecipitation (IP), Co-Immunoprecipitation (Co-IP), and Pulldown 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.

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.

Can Dynabeads Streptvidin magnetic beads be boiled?

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

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.

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

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.

Safety and Handling

WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov

For Research Use Only.