Invitrogen™ Dynabeads™ M-280 Sheep Anti-Mouse IgG

Catalog No.	Quantity
11-202-D	10 mL
11-201-D	2 mL

Catalog No. 11-202-D Supplier Invitrogen™ Supplier No. 11202D

Description

Includes

2mL Dynabeads M-280 Sheep anti-Mouse IgG (10mg beads/mL)

Dynabeads M-280 Sheep anti-Mouse IgG beads are 2.8-μm monosized, monodispersed, superparamagnetic beads with affinity-purified polyclonal sheep anti-mouse IgG covalently bound to the bead surface.

Dynabeads M-280 Sheep anti-Mouse IgG beads are 2.8-μm monosized, monodispersed, superparamagnetic beads with affinity-purified polyclonal sheep anti-mouse IgG covalently bound to the bead surface. These beads are intended for use as a solid support for simple and efficient binding of mouse IgGs and their target proteins. The uniform, monodisperse, and non-porous Dynabeads magnetic beads make them an ideal choice for applications such as binding immunoglobulins, protein purification, sandwich immunoassays, immunoprecipitation (IP), Co-immunoprecipitation (Co-IP), and isolation of cells and microorganisms. The polyclonal sheep antibody binds mouse IgG1, IgG2a, and IgG2b, and, with a lower reactivity, mouse IgG3 and IgM. Human cross-reactivity is minimal.

Benefits of Dynabeads M-280 Sheep anti-Mouse IgG beads include:

• Speed—isolate protein in less than 40 minutes
• Selectivity—binds most mouse IgG subclasses, very low non-specific binding
• Flexibility—no columns, centrifugations, or time-consuming pre-clearing required
• Automation ready—automation protocols available with the KingFisher Sample Purification instruments

Great signal to noise ratio

Dynabeads M-280 Sheep anti-Mouse IgG beads covalently couple the secondary sheep antibodies to a hydrophobic surface, which means the non-specific hydrophobic interactions are reduced to a minimum. Since this interaction is the main driver of unwanted protein binding, Dynabeads magnetic beads help ensure a great signal-to-noise ratio. This Dynabeads magnetic bead platform binds any mouse IgG antibody in a solution and can therefore become a powerful tool in affinity purification.

Dynabeads immunoprecipitation protocol is fast and easy

Add the target specific primary mouse IgG antibody directly to the sample (indirect technique) or first pre-coat the target antibody onto the Dynabeads M-280 Sheep Anti-Mouse IgG beads (direct technique). Regardless of which technique is used, when the Dynabeads M-280 Sheep anti-Mouse IgG beads are mixed with the sample, they bind to the target. The manual IP protocol is simple and can be performed in less than 40 minutes with 3 easy bind-incubate-elute steps. The procedure does not require any pre-clearing due to the low non-specific binding and uses very little antibody while still obtaining a high IP yield, thus saving both time and cost per IP.

The antibody-coated beads can be used in a variety of IP applications such as Co-IP, chromatin IP (ChIP/ChIP sequencing), RNA IP (RIP, RIP sequencing), small-scale IgG purification, and protein purification. The isolated pure target protein can be used in downstream western blot, mass spectrometry analysis, sequencing, etc.

Automation-ready for use with KingFisher purification systems

The 2.8-μm magnetic beads are ideal for high-throughput enrichment and can be automated using any of our KingFisher sample purification systems.

Commercial supply

Our manufacturing sites are ISO 13485-certified. Bead characteristics and manufacturing conditions help ensure consistency and batch reproducibility making them an ideal choice for commercial supply. If you are in the process of customizing Dynabeads Sheep anti-Mouse IgG beads in a commercial product or service or need a larger bulk volume of this product, please contact us at oemdynal@lifetech.com or see our Dynabeads OEM page.

Learn more about Dynabeads magnetic beads and KingFisher Sample Purification Systems:

• See our immunoprecipitation selection table, data, and references
• Dynabeads magnetic beads selection guide
• See magnets for Dynabeads magnetic beads separations
• KingFisher automation protocols
• Watch a video about the KingFisher Flex instrument

Order Info

Shipping Condition: Room Temperature

Specifications

• Concentration: 10 mg/mL
• Description: Polyclonal sheep anti-mouse IgG covalently bound to Dynabeads
• Material: Polystyrene
• Content And Storage: Dynabeads M-280 Sheep Anti-Mouse IgG is supplied in PBS, pH 7.4 w/0.1% BSA, 0.02% NaN₃ Store at 2°C to 8°C.
• Diameter (Metric): 2.8 μm
• For Use With (Equipment): KingFisher™ Sample Purification Systems, DynaMag™ Magnets
• High-throughput Compatibility: High-throughput Compatible
• Shipping Condition: Ambient temperature
• Reactivity: Binds mouse IgG1, IgG2a and IgG2b. Low reactivity towards mouse IgG3 and IgM.
• Quantity: 10 mL
• For Use With (Application): Protein Purification
• Target: Proteins
• Type: Antibody Coated Bead
• Ligand Type: Antibody
• Species: Sheep
• Format: Beads in suspension
• Color: Brown
• Certifications/Compliance: ISO9001 and ISO13485
• Regulatory Status: For Research Use Only
• Uniformity: Monosized 2.8 μm (CV <5%)

Frequently Asked Questions (FAQs)

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.

My Dynabeads magnetic beads are not pelleting well with the magnet. Do you have any suggestions for me?

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.

I have a long double-stranded DNA fragment I would like to isolate. What product do you recommend?

For biotin-labled DNA that is less than 1 kb, we recommend you use Dynabeads M270 Streptavidin and MyOne C1 magnetic beads. We recommend our Dynabeads KilobaseBINDER Kit, which is designed to immobilize long (>1 kb) double-stranded DNA molecules. The KilobaseBINDER reagent consists of M-280 Streptavidin-coupled Dynabeads magnetic beads along with a patented immobilization activator in the binding solution to bind to long, biotinylated DNA molecules for isolation. Please see the following link (https://www.thermofisher.com/us/en/home/life-science/dna-rna-purification-analysis/napamisc/capture-of-biotinylated-targets/immobilisation-of-long-biotinylated-dna-fragments.html) for more information in regards to long biotinylated DNA fragment isolation.

Can I use Dynabeads magnetic beads to isolate single-stranded DNA templates?

Yes, Dynabeads magnetic beads can be used to isolate single-stranded DNA. Streptavidin Dynabeads magnetic beads can be used to target biotinylated DNA fragments, followed by denaturation of the double-stranded DNA and removal of the non-biotinylated strand. The streptavidin-coupled Dynabeads magnetic beads will not inhibit any enzymatic activity. This enables further handling and manipulation of the bead-bound DNA directly on the solid phase. Please see the following link (https://www.thermofisher.com/us/en/home/life-science/dna-rna-purification-analysis/napamisc/capture-of-biotinylated-targets/preparing-single-stranded-dna-templates.html) for more information in regards to single-stranded DNA capture.

What is the magnetic susceptibility for Dynabeads magnetic beads?

Magnetic susceptibility is a measure of how quickly the beads will migrate to the magnet. This will depend on the iron content and the character of the iron oxide. The magnetic susceptibility given for the Dynabeads magnetic beads is the mass susceptibility, given either as cgs units/g or m^3/kg (the latter being an SI unit). For ferri- and ferromagnetic substances, the magnetic mass susceptibility is dependent upon the magnetic field strength (H), as the magnetization of such substances is not a linear function of H but approaches a saturation value with increasing field. For that reason, the magnetic mass susceptibility of the Dynabeads magnetic beads is determined by a standardized procedure under fixed conditions. The magnetic mass susceptibility given in our catalog is thus the SI unit. Conversion from Gaussian (cgs, emu) units into SI units for magnetic mass susceptibility is achieved by multiplying the Gaussian factor (emu/g or cgs/g) by 4 pi x 10^-3. The resulting unit is also called the rationalized magnetic mass susceptibility, which should be distinguished from the (SI) dimensionless magnetic susceptibility unit. In general, magnetic mass susceptibility is a measure of the force (Fz) influencing an object positioned in a nonhomogenous magnetic field. The magnetic mass susceptibility of the Dynabeads magnetic beads is measured by weighing a sample, and then subjecting the sample to a magnetic field of known strength. The weight (F1) is then measured, and compared to the weight of the sample when the magnetic field is turned off (F0). The susceptibility is then calculated as K x 10^-3 = [(F1-F0) x m x 0.335 x 10^6], where K is the mass susceptibility of the sample of mass m. The susceptibility is then converted to SI units.

How can I determine coupling efficiency of Dynabeads magnetic beads?

There are different methods to check binding of ligands to the beads, including optical density (OD) measurement, fluorescent labeling, and radioactive labeling.

For OD measurement, you would measure the OD of the ligand before immobilization to the beads and compare it with the ligand concentration that is left in the supernatant after coating. This gives a crude measurement of how much protein has bound to the beads.

Protocol:

1.Set spectrophotometer to the right wavelength. As a blank, use the Coupling Buffer.
2.Measure the absorbance of the Pre-Coupling Solution. A further dilution may be necessary to read the absorbance, depending upon the amount of ligand added.
3.Measure the absorbance of the Post-Coupling Solution. A dilution may be necessary to read the absorbance.
4.Calculate the coupling efficiency, expressed as the % protein uptake, as follows. [(Pre-Coupling Solution x D) - (Post-Coupling Solution x D)] x 100/(Pre-Coupling Solution x D) where D = dilution factor.

For fluorescent labeling, we suggest negatively quantifying the amount of ligand bound by measuring ligand remaining in the coupling supernatant (compared to the original sample), rather than directly measuring the ligands on the beads. Add labeled ligand to the beads, and measure how much ligand is left in the supernatant (not bound to the beads). By comparing this with the total amount added in the first place, you can then calculate how much of the ligand that has been bound to the beads. Keep in mind that the Dynabeads magnetic beads are also autofluorescent, which is why direct measuring of fluorescence of the bead-bound ligands is not recommended, but rather this indirect approach. The label could be, for example, FITC/PE. Some researchers perform a direct approach with success (using a flow cytometer).

Radioactive labeling is the most sensitive method of the three, but it is also the most difficult one. It involves radioactively labeling a portion of the ligand. We use radiolabeled I-125 in tracer amounts and mix it with "cold" ligands in a known ratio before coupling. The absolute quantities for the ligand on the beads should be obtained by measuring the beads in a scintillation (gamma) counter and comparing the cpm with a standard.

Protocol:

1.Take out an appropriate amount of beads and wash the beads in 1 mL of binding buffer.
2.Pipette out desired amount of human IgG in a separate tube.
3.Mix the human IgG with I-125-labeled human IgG (30,000 - 100,000 cpm).
4.Dilute the mixture of human IgG and I-125-labeled human IgG to 100 mL in binding buffer.
5.Incubate for 30 minutes at room temperature and measure the cpm in a scintillation counter.
6.Wash the beads (with coating) four times, and measure cpm again.
The % binding is calculated by using the equation : (cpm after washing/cpm before washing)x100%.

What sizes do you offer for the Dynabeads magnetic beads?

Dynabeads magnetic beads come in three sizes: 4.5 µm (M-450), 2.8 µm (M-270/M-280), and 1 µm (MyOne beads). The largest of the Dynabeads magnetic beads is ideal for big targets like cells. The 2.8 µm beads are recommended for proteomics and molecular applications. The smallest of the beads, 1 µm, are ideal for automated handling.

Can Dynabeads magnetic beads be sonicated?

In general, short sonication is a good way to reduce aggregation of the beads and ensure optimal homogenous conditions at the time of ligand addition when coating the beads. When target is bound to the beads, more care is needed, as the binding might break. The streptavidin beads themselves should tolerate sonication. We have not tested sonication for long periods, but 5 minutes is fine. We do not have information about the streptavidin-biotin interaction being broken by such treatment.

Can Dynabeads magnetic beads be sterilized?

If desired, the uncoated epoxy or tosylactivated beads can be sterilized by washing with 70% ethanol. Coated beads cannot be sterilized.

What are Dynabeads magnetic beads?

Dynabeads magnetic beads are uniform, non-porous, superparamagnetic, monodispersed and highly cross-linked polystyrene microspheres consisting of an even dispersion of magnetic material throughout the bead. The magnetic material within the Dynabeads magnetic beads consists of a mixture of maghemite (gamma-Fe2O3) and magnetite (Fe3O4). The iron content (Fe) of the beads is 12% by weight in Dynabeads magnetic beads M-280 and 20% by weight in Dynabeads magnetic beads M-450. The Dynabeads magnetic beads are coated with a thin polystyrene shell which encases the magnetic material, and prevents any leakage from the beads or trapping of ligands in the bead interior. The shell also protects the target from exposure to iron while providing a defined surface area for the adsorption or coupling of various molecules.

Uniformity of bead size and shape provides consistent physical and chemical properties. These uniform physical characteristics lead to high-quality, reproducible results.

The Dynabeads magnetic beads are available in three different sizes: 4.5 µm (M-450 beads), 2.8 µm (M-270/M-280 beads) and 1 µm (MyOne beads). as well as our Protein Immunoprecipitation (IP), Co-Immunoprecipitation (Co-IP), and Pulldown Support Center.

Can I use Dynabeads secondary antibody coated beads for immunoprecipitation (IP)?

We supply two secondary antibody coated 2.8 micron beads for immunoprecipitation:
Dynabeads M-280 Sheep anti-Mouse IgG magnetic beads (Cat. Nos. 11201D and 11202D) to be used when your primary antibodies are derived from mouse.
Dynabeads M-280 Sheep anti-Rabbit IgG magnetic beads (Cat. Nos. 11203D and 11204D) to be used when your primary antibodies are derived from rabbit serum.

For how long can Dynabeads magnetic beads be stored?

Storage should be at 2-8 degrees C. Freezing Dynabeads magnetic beads is not recommended. Provided the Dynabeads magnetic beads are stored correctly, quality is guaranteed until the expiration date stated on the label. as well as our Protein Immunoprecipitation (IP), Co-Immunoprecipitation (Co-IP), and Pulldown Support Center.

How should I store coated Dynabeads magnetic beads if I want to reuse them?

Dynabeads magnetic beads coated with antibody/ligand may be stored at 2-8 degrees C without loss of antigen binding capacity. For long-term storage, a final concentration of 0.02% NaN3 may be added to the antibody-coupled beads in a physiological buffer. Please note that not all coupled antibodies retain their function in long term storage. Verify your coupled antibody stability by testing in small scale. After storage, coated Dynabeads magnetic beads should be washed once in PBS/BSA for 5 min before use.

How can I dissociate isolated proteins from Dynabeads magnetic beads?

Standard elution methods are used to dissociate the isolated protein from Dynabeads magnetic beads. The most suitable elution method depends on the characteristics of the isolated protein and the desired downstream application of the eluted protein. In many cases, Dynabeads magnetic beads can be recovered for reuse after elution. Some standard elution methods are listed below.

-pH change: elution can be achieved by reducing pH (for example, by using 0.1 M citrate (pH 2-3) as the elution buffer). Dynabeads magnetic beads are stable between pH 4-13. If the Dynabeads magnetic beads are exposed for a prolonged period of time to pH below 4, the beads may be adversely affected.

-Change of ionic strength: high-salt concentration buffers (e.g., NaI, KI, MgCl, KCl) can be used to elute isolated proteins. Optimization is required, by step-wise elution starting at 1 M and increasing to 3 M.

-Affinity elution: with this method, the eluting agent competes for the binding of the protein or the binding of the ligand e.g., elution of glycoproteins from a lectin coupled to Dynabeads magnetic beads may be achieved by the addition of the free sugar.

-Denaturing eluents: as a last resort, denaturing eluents such as chaotropic salts may be used to alter the structure of the protein. The proteins on the bead surface and the eluted proteins will be denatured.

-Polarity reducing agents : substances that reduce the polarity of the buffer often disrupt the hydrophobic interactions between antibody and protein. Dioxane or ethylene glycol may be used to reduce the polarity of the eluent. as well as our Protein Immunoprecipitation (IP), Co-Immunoprecipitation (Co-IP), and Pulldown Support Center.

What is the definition of superparamagnetic, and what does this mean for my cell isolation application with Dynabeads magnetic beads?

Superparamagnetic means that the Dynabeads magnetic beads exhibit magnetic properties when placed within a magnetic field, but have no residual magnetism when removed from the magnetic field.

This means that your targeted cells, proteins, or nucleic acids are only subjected to magnetic forces during the time the beads are on the magnet. The beads do not aggregate, but remain evenly dispersed in suspension.

Are the antibodies on your Dynabeads magnetic beads for cell isolation/activation/expansion covalently bound to the beads?

Yes. The antibodies are covalently bound and should be very stable in your applications.

What is the average shelf life of Dynabeads magnetic beads?

Depending on the antibody coated on the Dynabeads magnetic beads, the shelf life can vary from 24-36 months.
Some kits may have 18 months shelf life depending on other components supplied in the kit. The kits are guaranteed for 6 months from when you receive them. as well as our Protein Immunoprecipitation (IP), Co-Immunoprecipitation (Co-IP), and Pulldown Support Center.

What do the designations M-280, M-270, and MyOne mean on Dynabeads magnetic beads?

The M stands for magnetic. M-280 refers to hydrophobic 2.8 micron beads, while M-270 refers to hydrophilic 2.8 micron beads. MyOne refers to 1 micron beads. as well as our Protein Immunoprecipitation (IP), Co-Immunoprecipitation (Co-IP), and Pulldown Support Center.

What is the detection limit when using Dynabeads magnetic beads for immunoprecipitation (IP)?

Answering this question is not straightforward. It will depend on the detection method. When using HRP (horseradish peroxidase)-based detection system or radioactivity in combination with a good antibody, very little target is required. More target is required when using an AP (alkaline phosphatase)-based detection system. When a sensitive detection system is used, detection will most likely be in the nanogram range. In some cases, pictograms of target can be detected.

For protein complex pulldown, does the Dynabeads Co-immunoprecipitation Kit work better than the indirect immunoprecipitation (IP) method using the Dynabeads Protein A or G magnetic beads, or the secondary coated magnetic beads?

The Dynabeads Co-immunoprecipitation Kit is specially designed for protein complex pulldown only, not for simple IP. These beads are the Dynabeads M270 Epoxy (Cat. No. 14301) beads and are used for covalent binding of the antibody so it will not be co-eluted off with the target complex during mild elution. The kit also contains a buffer system that should make it easier to optimize for recovering the complex.

With the Dynabeads Protein A or G magnetic beads, there is only a non-covalent binding between the Protein G on the beads and the antibody. Thus, the antibody will be co-eluted with the target protein unless you crosslink it to the beads beforehand. In general, we recommend the Dynabeads Co-immunoprecipitation Kit for complex pulldown, especially if you are working with large, labile complexes or if your downstream application is mass spectrometry.

Secondary coated Dynabeads magnetic beads (like the Dynabeads anti-mouse IgG beads) can also be used for IP, but, the drawback when compared to Dynabeads Protein A or G magnetic beads, is that they will only work with an antibody from 1 species. However, the binding between the primary antibody and the secondary antibody might be a bit stronger than between Protein A or G and the antibody. Hence, you can apply more stringent washing conditions. That being said, Dynabeads Protein A and G magnetic beads should give a very low background.

What is the elution volume when using Dynabeads magnetic beads for immunoprecipitation (IP)?

Within practical limits, the elution volume can be scaled up or down to suit your experiment. However, volumes less than 10 µL become more difficult to work with. In addition, the amount of target is important. If you have a lot of beads with a lot of bound target in a small elution volume, your elution may not be very efficient. Typically, 15-100 µL of beads may be eluted in 30 µL. For efficient recovery of the antigen and/or binding partners, the elution volume should at minimum equal the volume of the beads.

How can I quantify the amount of antibody bound to Dynabeads magnetic beads?

There are several methods to quantify the amount of antibody bound to the beads. The crudest method is to measure the concentration of antibody in the coupling reaction before and after antibody attachment. Either fluorescence measurements or absorbance at 280 nm can be used. Alternatively, you could measure the amount of antibody bound to the beads by fluorescence, chemiluminescence, or radiolabeling detection methods. as well as our Protein Immunoprecipitation (IP), Co-Immunoprecipitation (Co-IP), and Pulldown Support Center.

How long should I incubate my antibody with the lysates?

Incubation time will depend on the immunogenicity of the primary antibody and its binding affinity with the specific antigens. For a good primary antibody, 30-40 minutes incubation should work well. If you are working with a poor antibody or a very low-abundance protein, you could try to increase binding by incubating overnight. However, this also increases the chance of background protein binding.

When should I covalently bind the antibody to the Dynabeads surface?

If the target protein has the same molecular weight as the heavy or light chain antibody, we would recommend covalently binding the antibody to the bead surface. This can be done by either crosslinking the antibody to the Dynabeads Protein A or G magnetic beads, or secondary coated beads, or by using one of the surface-activated Dynabeads magnetic beads. as well as our Protein Immunoprecipitation (IP), Co-Immunoprecipitation (Co-IP), and Pulldown Support Center.

What are the general advantages of using Dynabeads magnetic beads for protein isolation?

Using Dynabeads magnetic beads for protein isolation provides several advantages:

-Rapid binding kinetics: since the number of beads per volume for Dynabeads is approximately 1,000 times higher than for the same volume of a Sepharose slurry, the probability for Dynabeads magnetic beads to hit the target is far greater.

-Incubation time: due to the rapid binding kinetics, the protocol is usually very short.
-Low background: due to the rapid binding kinetics and the short incubation time, the background is also very low.
-Trapping of impurities: the beads offer no internal volume for binding or trapping of impurities.
-Low antibody consumption: this is because Dynabeads magnetic beads are nonporous, uniform superparamagnetic, monodispersed, highly crosslinked polystyrene microspheres consisting of an even dispersion of magnetic material throughout the bead. The beads are coated with a thin layer of a highly crosslinked polystyrene shell that encases the magnetic material and prevents any leakage from the beads or trapping of ligands in the bead interior. The outer layer also provides a defined surface area for the adsorption or coupling of various molecules such as antibodies. Uniformity of bead size and shape provide consistent physical and chemical properties. These uniform physical characteristics lead to high-quality, reproducible results.
-Reproducibility: due to easier practical handling, such as pipetting. No centrifugation steps or preclearing are required.

Are Dynabeads magnetic beads compatible with dithionite, DTT, and EDTA?

No. Not only is dithionite a reducing agent, but the strong affinity of the dithionite ion for bivalent and trivalent metal cations (M2+, M3+) allows it to enhance the solubility of iron, making it a chelating agent. As a result, the iron in the Dynabeads magnetic beads is reduced and pulled out when they are exposed to dithionite. The same is observed if Dynabeads magnetic beads are exposed to DTT and EDTA. With EDTA, we highly recommend checking the minimal amount of EDTA that your specific molecules would tolerate for binding to the Dynabeads, and if it will affect your specific application. For some applications, low concentrations of EDTA can be tolerated by Dynabeads. On the other hand, using 10 mM EDTA with heating affects the binding of biotin molecules to Dynabeads streptavidin. as well as our Protein Immunoprecipitation (IP), Co-Immunoprecipitation (Co-IP), and Pulldown Support Center.

Are Dynabeads magnetic beads compatible with Urea?

Yes, they are compatible with 6-8 M Urea when used during post-coupling steps.

Are Dynabeads magnetic beads compatible with centrifugation?

Dynabeads magnetic beads, being magnetic in nature are really not designed to be centrifuged. That being said, the beads themselves are compact, as the pores in the polymer matrix are filled with magnetic material and coated with a final outer polymer shell that will further add to the rigidity of the beads. Hence, pressure should theoretically not be a problem for the beads themselves, but the force exerted by the beads on surrounding cells in the pellet may be detrimental to the cells. as well as our Protein Immunoprecipitation (IP), Co-Immunoprecipitation (Co-IP), and Pulldown Support Center.

What are the benefits of using magnetic beads in immunoprecipitation (IP) experiments?

Magnetic beads, unlike agarose beads, are solid and spherical, and antibody binding is limited to the surface of each bead. While magnetic beads do not have the advantage of a porous center to increase the binding capacity, they are significantly smaller than agarose beads (1 to 4 µm), which collectively gives them adequate surface area-to-volume ratios for optimum antibody binding.

High-power magnets are used to localize magnetic beads to the side of the incubation tube and out of the way to enable cell lysate aspiration without the risk of also aspirating immune complexes bound to the beads. Magnetic separation avoids centrifugation, which can break weak antibody-antigen binding and cause loss of target protein.

However, an issue with the use of magnetic beads is that bead size variations may prevent all beads from localizing to the magnet. Additionally, while immunoprecipitation using agarose beads only requires standard laboratory equipment, the use of magnetic beads for immunoprecipitation applications requires high-power magnetic equipment that can be cost-prohibitive. Read more about our Magnetic Immunoprecipitation Products (https://www.thermofisher.com/us/en/home/life-science/protein-biology/protein-assays-analysis/immunoprecipitation.html#products).

Safety and Handling

WARNING: Cancer - www.P65Warnings.ca.gov

For Research Use Only. Not for use in diagnostic procedures.