Bangs Laboratories, Inc. is a manufacturer of uniform polymer, silica and magnetic microsphere products for diagnostic, research and flow cytometry applications.

They also manufacture many specialty products to support validation and QC programs for analytical instruments, including a broad portfolio of fluorescent, count, size and cell viability standards.

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Bangs Laboratories manufactures quality specialty microspheres for a variety of immunoassay, molecular biology, and cell biology applications. We supply polymeric, silica, and superparamagnetic particles offered with a variety of surface functional groups, with plain and fluorescent dyes, and pre-coated with generic binding proteins, such as streptavidin and secondary antibodies.

Microspheres offer a highly convenient and flexible system for developing reagents for assays and bioseparations, and for use as instrument standards. With many varieties of microspheres available, it is important to think about the demands the application will place on them when choosing a base bead. Physical and optical properties should be considered in the context of handling and detection, and thought should also be given to requirements for diameter and size distribution, composition, surface chemistry, and any other needed properties.

Microspheres offer a highly convenient and flexible system for test and assay reagent development. Many different types of spheres are available to address the diverse and evolving needs of research and commercial aims – polymer, silica, and magnetic, with different surface chemistries in a range of sizes. Beads offer a large specific surface area for binding, permit efficient capture and isolation of target, and they are highly amenable to automation and miniaturization. See our TechNote on Microsphere Selection for tips on choosing beads for different test and assay formats. Please check out our Microsphere Reagent Development Guide, an overview of products that we manufacture for IVD test / assay development, and considerations for products selection and handling,


Test / Assay Format Bead Size Bead Type Coating Strategy Detection Strategy Doc.
Turbidimetric 50nm – 500nm Undyed- (plainCOOH) Covalent Turbidimetry TN304
Magnetic Chemiluminescence 1 – 5 µm ProMag® HP Covalent Luminescence PDS 743
Flow cytometric 2µm – 15µm QuantumPlex™  QuantumPlex™M Covalent or streptavidin / biotin Flow cytometer PDS 250PDS 235
Bead “ELISA” 1- 3 µm ProMag®, ProMag® HP Covalent Spectrophotometer TN301
Lateral Flow 0.1µm – 0.4µm DyedEuropium Chelate Covalent or adsorption Visual or Automated Reader TN303
Lateral Flow – Boulders in the Stream 0.1µm – 0.4µm mobile phase, ~2µm – 3µm capture phase Dyed (visible) mobile phase, Undyed capture beads- (plainCOOH) Covalent or adsorption Visual TN303
Dipstick 0.1µm – 0.4µm Dyed (visible) Covalent or adsorption Visual TN303
Latex Agglutination Test (LAT) 0.2µm – 1.0µm Undyed- (plainCOOH) or visibly dyed Covalent or adsorption Visual TN301TN303

Magnetic microparticles offer a highly convenient means to conduct a variety of bioseparations. Particles may be coated with antibodies, lectins, or oligonucleotides to effect separations of specific cell populations or target sequences, and kits and protocols are available for nonspecific or targeted isolations. We offer a broad range of magnetic particle-based kits and specific coatings for the enrichment of leukocyte populations, depletion of abundant proteins from serum, and isolation of glycoproteins and nucleic acids.

Many of our bioseparation products are based on BioMag® and BioMag®Plus magnetic particle technology. The irregular morphology affords much greater surface area than that of similarly sized spherical particles. The large surface area results in high capture efficiency with conservative use of particles.

Magnetic Microspheres magnetic response

Current applications in flow cytometry extend far beyond traditional lymphocyte immunophenotyping. Flow cytometry is used for such varied applications as cell cycle analysis, telomere length determinationmicrovesicle analysis, receptor occupancy, phagocytosis and many other studies. We offer standards to support these types of assays, for the standardized instrument set-up and comprehensive quality assurance essential for achieving accurate and consistent results within a study, and generating comparable data between instruments and laboratories.

Many diagnostic and imaging applications rely on fluorescent microspheres for detection of binding events or signal enhancement. Addressable bead populations may be created with different intensities of fluorescence for the development of multiplexed suspension arrays, and small fluorescent spheres can function as reporters for ELISA-type assays. Fluorescent microspheres are also useful for fluid tracing, cell tracking, or phagocytosis studies.

Phagocytosis is one of the first lines of defense against invading microorganisms. It is also important for the processes of tissue remodeling and removal of senescent cells. As important as phagocytosis is, to date no single model can adequately describe this extremely complex process. This is due in part to the wide variety of receptors that can stimulate phagocytosis and the ability of the microorganisms themselves to influence the process. Synthetic polymeric particles are used extensively to study phagocytosis, and they may be coated with opsonins to enhance uptake.

Filter challenge studies often make use of highly uniform undyed, fluorescent, or visibly dyed polystyrene microspheres as surrogates for biologic or environmental particulates in order to reduce potential health risks and costs associated with the use of pathogens, atomized oils, etc.

Viability and concentration determinations are integral to the cell culture technologies used in recombinant protein production and a wealth of research and diagnostic applications. Methods for determining cell viability and counts may rely on visible dye (trypan blue) exclusion and imaging using a hemocytometer or automated analyzer, or cell labeling with membrane-impermeable fluorescent dyes (propidium iodide, DAPI, HoechstLIVE/DEAD) with flow cytometric analysis. We offer a range of products that support these methods and instruments, and invite you to contact us with any questions or additional needs.

Meet Magnefy™, our ~1µm high-performance superparamagnetic microspheres. As high surface area / high surface titer microparticles with a rapid separation profile, Magnefy offer a performance-driven solid phase for magnetic particle-based applications, including SPRI-based total DNA isolation (COOH), and molecular- and immunoassays. Contact us today to explore using Magnefy as your OEM magnetic SPRI bead. See Magnefy™ New Product Development: Magnetic Particle Characterization & QC Testing


Catalog Number Description
MFY0002 Magnefy™ • COOH 1µm
MFYS1N Magnefy™ • SA 1µm


  • Meyer M, Stenzel U, Hofreiter, M. (2008). Parallel tagged sequencing on the 454 platform. Nature Protoc; 3(2), 267.
  • Hawkins TL, O’Connor-Morin T, Roy A, Santillan C. (1994). DNA purification and isolation using a solid-phase. Nucleic Acids Res; 22(21), 4543-4.


BioMag® and ProMag™ products support specific and non-specific (total) nucleic acid isolation through the immobilization/capture of biotinylated oligos and the purification of mRNA or total DNA.


Streptavidin-coated magnetic particles have been used for the isolation of biotinylated PCR amplicons. The irregular morphology of BioMag® offers high binding capacities and efficient isolations.


Catalog Number Description Concentration (mg /mL) Volume (mL)
BM568 BioMag® Streptavidin, Nuclease-free 1 10 & 25
BM551 BioMag® Streptavidin 5 5 & 50
BP628 BioMag®Plus Streptavidin 5 10
BP621 BioMag®Plus Streptavidin / Biotin Binding Kit 5 5


ProMag® are highly uniform polymer-based magnetic spheres available in diameters of 1µm and 3µm. A unique surface means low nonspecific binding in protein-based systems, and superior handling without the use of surfactant. These high-binding beads are suitable for use across a range of research and diagnostic applications, whether you’re working at laboratory scale or have the more stringent requirements of high throughput applications. ProMag® Streptavidin are supplied as ~1% solids (w/v) aqueous suspensions.

Catalog Number Description
PMS3HP ProMag® HP 3 Series • Streptavidin
PMS1N ProMag® 1 Series • Streptavidin
PMS3N ProMag® 3 Series • Streptavidin


Our many magnetic particle products uniquely address a wide range of applications in the life sciences, including cell isolations, affinity purifications, immunoassays, molecular assays. For development efforts, our  Magnetic Particle Sampler Packs allow you to test different particles to find which yield optimal performance characteristics in your specific system.

Catalog Number Description
21950 Streptavidin Magnetic Sampler Pack MFYS1N, Magnefy 1µm SA – 1mL (1% solids) PMS1N, ProMag 1 Series SA – 1mL (1% solids) PMS3HP, ProMag HP 3μm SA – 1mL (1% solids) BP628, BioMagPlus SA – 2mL (5mg / mL)


Nuclease-free suspensions of BioMag® with covalently-bound Oligo dT(20) are used for the efficient isolation of polyadenylated mRNA from total RNA, tissue or cell lysate.

Catalog Number Description Concentration (mg / mL) Volume (mL) Number Of Reations
BM569 BioMag® mRNA Purification System 5 2 20 × 100µg total RNA; or 10 × 50 – 100 mg tissue; or 10 × lysate from 5 × 106 cells
BM529 BioMag® Oligo dT (20) 5 2 20 × 100µg total RNA

As researchers around the world work to advance solutions to combat COVID-19 and other diseases, we remain committed to manufacturing reagents that are critical to many of these important programs. We are here to support your efforts, and invite you to contact us if we can be of help in realizing current supply continuity plans, future business resumption efforts, or even to address routine product or technical questions.


PCR-based  tests look for viral genetic material (RNA) Magnefy, our ~1µm carboxylated superparamagnetic microspheres may be used for nucleic acid isolations. They offer high surface area and high surface titer with a rapid uniform magnetic response profile.

Catalog Number Description Product Data Sheet Safety Data Sheet
MFY0002 Magnefy™ • COOH 1µm PDS 756.pdf SDS MY100.pdf


Our highly-fluorescent europium (III) nanoparticles offer exceptional stability, in addition to well-functionalized carboxylated surfaces for the covalent attachment of ligand. Our Eu (III) nanoparticles have been used to develop highly sensitive assays (microplate, lateral flow) based on time-resolved (TRF) fluorescence and as particulate labels in chemiluminence assays.

Catalog Number Description Nominal Diameter Specification Range Product Data Sheet
FCEU001 Europium Chelate PS – COOH 0.10µm 0.090 – 0.110µm PDS 741.pdf
FCEU002 Europium Chelate PS – COOH 0.20µm 0.190 – 0.210µm PDS 741.pdf
FCEU003 Europium Chelate PS – COOH 0.30µm 0.270 – 0.330µm PDS 741.pdf


Our ViaCheck standards mimic the characteristics of live and dead cells may be used to validate cell viability analyzers.  Our Quantum™ Flow Cytometry standards may be utilized to demonstrate transfection efficacy, and for cellular surface marker expression analysis.

Catalog Number Description Volume (mL) Product Data Sheet Safety Data Sheet
VC10B ViaCheck™ 0% Viability Control 20 PDS 706.pdf SDS ST352.pdf
VC25B ViaCheck™ 25% Viability Control 20 PDS 706.pdf SDS ST352.pdf
VC20B ViaCheck™ 50% Viability Control 20 PDS 706.pdf SDS ST352.pdf
VC30B ViaCheck™ 75% Viability Control 20 PDS 706.pdf SDS ST352.pdf
VC40B ViaCheck™ 90% Viability Control 20 PDS 706.pdf SDS ST352.pdf
VC50B ViaCheck™ 100% Viability Control 20 PDS 706.pdf SDS ST352.pdf
VC50N ViaCheck™ Concentration Control (0.5 × 106) 20 PDS 711.pdf SDS ST353.pdf
VC60N ViaCheck™ Concentration Control (1 × 106) 20 PDS 711.pdf SDS ST353.pdf
VC70N ViaCheck™ Concentration Control (4 × 106) 20 PDS 711.pdf SDS ST353.pdf
VC80N ViaCheck™ Concentration Control (8 × 106) 20 PDS 711.pdf


Catalog Number Description Units
VC10BSS ViaCheck™ 0% Viability Control SingleShots™ 25 or 75
VC25BSS ViaCheck™ 25% Viability Control SingleShots™ 25 or 75
VC20BSS ViaCheck™ 50% Viability Control SingleShots™ 25 or 75
VC30BSS ViaCheck™ 75% Viability Control SingleShots™ 25 or 75
VC40BSS ViaCheck™ 90% Viability Control SingleShots™ 25 or 75
VC50BSS ViaCheck™ 100% Viability Control SingleShots™ 25 or 75
VC50NSS ViaCheck™ Concentration Control (0.5 × 106) SingleShots™ 25 or 75
VC60NSS ViaCheck™ Concentration Control (1 × 106) SingleShots™ 25 or 75
VC70NSS ViaCheck™ % Concentration Control (4 × 106) SingleShots™ 25 or 75
VC80NSS ViaCheck™ % Concentration Control (8 × 106) SingleShots™ 25 or 75


1. What is the surface charge or zeta potential of your particles?

We regrettably don’t have the ability to measure the surface charge of our particles, but based on many studies that have measured the surface charge of our particles, as well as our personal experience, we expect most uncoated particles to have a net negative surface charge. This includes our plain polystyrene, carboxylated polystyrene, amine polystyrene, and their equivalent dyed counterparts. Coated protein will likely take on the surface charge of the corresponding protein.

2. Do you have positively charged particles?

By default, we do not offer particles with a known positive surface charge. While amine groups are thought to contribute localized positive charge, the net charge of the particle surface is not necessarily positive. Positively charged particles can be created by further modifying our plain or carboxylated polystyrene, either through surface conversions or coatings with cationic polymers.

3. Do you measure the amount of carboxyl or amine groups on your beads?

We measure the carboxyl titer for the vast majority of our carboxylated beads, and results can be found alongside the product by clicking on catalog number of interest. Silica carboxyl do not come with titer estimates, although we do conduct qualitative streptavidin binding tests to confirm carboxyl group reactivity.

4. Do you measure the binding capacity of your beads?

Most of our protein coated products come with a binding capacity, which will be listed on the CoA and made available upon request.

5. How does Bangs attach their proteins for protein-coated particles?

Most protein-coated beads employ a base carboxylated bead, and the protein is subsequently covalently attached using EDAC-based methods. However, exceptions exist, so please inquire with our Technical group for more information.

6. What sizes do you offer?

Exact offerings depend on availability and product type. Size offerings generally start at 25 nm and go as high as 20 µm for our polystyrene beads, whereas silica is about 150 nm to 5 µm. Non-standard offerings may exceed these general ranges.

7. What are your beads made of?

Most of our products are of a polymer composition, principally polystyrene, but potentially PMMA or other proprietary polymers. We also produce silica beads, as well as some polymer and non-polymer paramagnetic particles.

8. Are the beads toxic? Can I use them in animals?

Polystyrene is generally considered non-toxic and is ubiquitously used in other industries that end up in direct contact with humans. Furthermore, many studies exist that cite the use of polystyrene or similar particles in cells and animal models. With that said, our products are for Research Use Only and have been supplied with added stabilizers that can be toxic to cells or other life. Individual use is at the user’s risk.

9. What is the refractive index of Polystyrene?

For PSI, we anticipate a refractive index of 1.59 at the 589 nm. For more RI values (and other info) visit our Material Properties page.

10. Are your particles smooth and spherical?

We do not measure the sphericity or surface roughness of our particles. In general, though, we expect the particles to be spherical. Acid-modified spheres (e.g. carboxylated) may have more associated surface roughness.

11. What size bead should I use?

Many of our users approach us with this question. The desired size will vary depending on the intended use. If unsure, you should first consult the relevant literature; many times a similar use has been reported can be used as an initial basis for selection. Keep in mind that while we’re happy to guide in the process, ultimately the decision needs to be made by the user. See Technote 201A.

12. What is the molecular weight of your beads

We do not evaluate the molecular weight of the polymer chains.

13. Are your beads porous?

We do not produce porous beads, all offerings should be viewed as non-porous.

14. Do you have SEM imaging you can share?

For the majority of our lots we do not offer SEM images. In limited instances, we have SEM images for select lots.

15. What is the particle concentration and particle count?

Particles will be provided at various concentrations depending on the type of product. For instance, we supply our plain polystyrene at 10% solids, or 100 mg of beads/mL. Particle count is not measured on most products unless it’s a speciality count product (such as our SureCount standards). Estimated counts are typically supplied on the product’s CoA and can be supplied on a requested basis as well.

16. What do you mean by washing?

Washing refers to an exchange of the suspending solution in which particles are suspended. Most users employ a centrifuge to pellet the beads, aspirate/decant the supernatant, then resuspend in the desired buffer type and volume. Washing can fulfill a variety of needs, including preparing the beads for various applications, or during coating procedures to remove residual reagents. See more in our Washing Technote.

17. At what speed should microspheres be centrifuged?

See our centrifugation chart. Beads below 0.5 µm should use alternative techniques, such as spin filters (Vivaspin) or dialysis.

18. Can I dry the beads?

Beads can be dried down; we do so on a limited basis for some of our products as a standard offering. Drying is a bit of an art form, so users will need to optimize extensively if they intend to pursue. Some level of aggregates must also be expected. For quick experimental efforts, see Technote 203A for a general drying protocol .

19. I want to put the beads into a different solution, is that ok?

Sure. Our polystyrene beads are stable in a wide variety of aqueous solutions, although do avoid organic solvents which will likely dissolve the beads. Crosslinked beads (look for DVB in the product description) will confer added resistance to temperature and organic solvents.  See our solvents listing; solvents not listed should be researched, or may be brought to our Technical group for review. Silica beads are much more chemically resistant and can be used in more challenging environments.

20. Are the beads provided sterile? If not, is it ok if I autoclave them?

None of our products are provided sterile, although the majority do contain sodium azide to help prevent microbial growth. Autoclaving our particle suspensions is strongly discouraged, as it will likely cause partial to severe particle aggregation. Refer to our Technical Support Document 726, Decontaminating Microspheres for other suggested methods.

21. How can I attach my protein to your particles?

A variety of methods exist. The most popular is by using carboxylated beads to covalently link to the amine groups of proteins or antibodies (Technote 205), or by using an affinity method such as biotin-protein to our streptavidin coated beads (Technote 101). Adsorption is also a common method, and relies on non-specific hydrophobic, ionic and Van der Waals forces (Technote 204). Other options exist, and choosing which approach to use is ultimately an independent decision.

22. How much protein should I use to coat?

Protein needs will vary greatly based on the particle diameter, protein of interest and intended use. The gold standard is to titrate the protein against the bead, then monitor for subsequent stability and performance. Initial estimates can be derived from the available functional groups and by using our surface saturation equation in Technote 205.

23. Your storage recommendations mention store at 2-8°C, and not to freeze. Why is that? I thought these were inert particles?

Storage temperatures are mainly aimed at preventing microbial growth throughout the product lifetime. Freezing, however, will cause the particles to severely and irreversibly aggregate, forming what looks like precipitates.  Speciality surface-modified fluorescent particles will need to keep the corresponding fluorochromes stability profile in mind as well. For instance, phycoerythrin (PE) and its tandems are well known to be quite temperature-sensitive.

24. What stabilizers do you provide in your particle suspensions?

Stabilizers present will vary depending on the product. Consult the CoA or SDS for specific product info (can be found on the website with the product). In general, most polymer bead suspensions will feature a surfactant and sodium azide (used as an antimicrobial). Protein-coated suspensions tend to have further additives, such as BSA and EDTA. Uncoated silica and some magnetic microparticles are free of stabilizers, again, consult the product CoA.

25. Do your particles melt, break, or otherwise dissolve?

Polymer microspheres should be stable under a wide range of conditions, and do not readily degrade. Exposure to very high temperatures or solvents can compromise the beads. Visit our Material Properties page and solvents/non-solvents listing for more information. Specific or unique conditions should be addressed with our Technical group before purchase.

26. What is the expiration policy?

Most suspensions of uncoated microparticles do not have an assigned expiration period. This is based on our expectation that the particles will not appreciably change over time, and is supported by our experience in handling particles. Some specialized uses or types of microparticles, however, do warrant expiration dating, including protein coated particles (due to the more labile nature of the protein), or particle standards (fluorescence, size, etc). In these instances, the expiration date will be printed on the CoA as well as on the bottle label. See more details about stability & storage here.

27. Can beads be used for phagocytosis?

Beads are commonly used in phagocytosis experiments, especially fluorescent beads. See  Technical Document 727 – Phagocytosis and Phagocytosis References for more info.

28. What QuickCal program should I select?

QuickCal is a program used to support our Quantum MESF and Quantum QSC kits. We offer a variety of formats to accommodate the different resolutions a cytometer’s software may offer. To choose the appropriate template type, review the channel values listed on our fluorescence histogram and compare that to the channel values listed on our website. Most commonly the log/log format is appropriate.


Bangs Laboratories offers a variety of equipment... Magnetic Separators Superparamagnetic particles have been used extensively in diagnostics and other research Read More...

Coupling Kits

Our coupling kits permit the covalent immobilzation of proteins to microparticles. We offer several kits featuring BioMag® superparamagnetic partcles and separations, Read More...

Accessory Reagents

Bangs Laboratories offers a variety of accessory products for use in microparticle reagent development. The collection includes crosslinking reagents and Read More...

Flow Cytometry

Hello Flow-ers, Flowbos, Cytometrians, or just fellow flow cytometry lovers. Welcome to our Flow Cytometry division!  We’ve been in beads Read More...

Instrument Standards

We manufacture a comprehensive range of standards for analytical instruments such as cell analyzers, particle sizers, flow cytometers, and fluorescence Read More...

Silica Microspheres

Inorganic supports, such as silica microspheres, have become increasingly important for a variety of applications. They offer the combined benefits Read More...

Dyed Polystyrene

Visibly dyed microspheres are frequently used in lateral flow tests and "latex" agglutination tests. Our polystyrene microspheres are impregnated with Read More...

Affinity Ligand Coated Microspheres

Affinity binding ligands can aid in the rapid development or streamlined production of microsphere reagents. They also provide the opportunity Read More...

Magnetic Isolation Products & Kits

Superparamagnetic particles have been utilized extensively in diagnostics and other research applications for the purification of cells and biomolecules, such Read More...

Fluorescent Microspheres

Fluorescent microspheres are a mainstay in diagnostics and life sciences research, finding use as fluorescent markers, assay substrates, and instrument Read More...

Flow Cytometry Products

Bangs Laboratory’s flow cytometry product suite includes products to check general instrument status, optics alignment, sensitivity, and linearity. We also Read More...

Magnetic Microspheres & Particles

Superparamagnetic particles have been utilized extensively in diagnostic and other research applications for the capture of biomolecules and cells. They Read More...

Polystyrene Microspheres

Polystyrene microspheres present a flexible platform for applications in diagnostics and bioseparations. They may be coated with recognition molecules, such Read More...

Microsphere Selection

Diameter Microsphere size may be critical to the proper function of an assay, or it may be secondary to other Read More…