Top 10 Carboxyl Polystyrene Microsphere Manufacturers Serving the USA in 2026

Quick Answer

Carboxyl polystyrene microspheres are available to US buyers from domestic particle manufacturers, major life science companies and international suppliers.

This 2026 guide presents ten companies with publicly available carboxylated polystyrene particles or closely related manufacturing capabilities. The entry numbers indicate the order of presentation. They do not represent independently tested product performance, revenue or US market share.

The suppliers serve different requirements. Some focus on catalogue quantities for research, while others support diagnostic development, customized surface chemistry, colored or fluorescent particles and larger-volume production.

Before selecting a supplier, compare the exact product rather than the company name alone. Important specifications include particle diameter, size distribution, carboxyl content, solids concentration, suspension formulation, batch documentation and supply conditions.

What “Serving the USA” Means

A company can serve US buyers without manufacturing every product in the United States. Supply may come from a domestic factory, a US sales office, a distributor or international shipment.

Buyers that require US manufacturing should request written confirmation of the production location for the selected product. A company address or US ordering channel does not establish where a particular microsphere is manufactured.

For international suppliers, confirm the shipping route, delivery time, required documentation and import arrangements for the actual destination.

This guide includes both US-based and international options so that buyers can compare catalogue availability, customization and commercial supply.

Ten Manufacturers and Suppliers to Compare

The appropriate supplier depends on the required particle specification, application, order volume and documentation. Inclusion in the table does not mean that every product is made in the USA or intended for use in clinical diagnostic procedures.

1. Polysciences

Polysciences offers Polybead carboxylate microspheres made from polystyrene with surface carboxyl groups. Its catalogue includes several particle diameters for research, assay development and biomolecule immobilization.

The company is relevant when a buyer wants a defined catalogue product with a specific diameter and package size. Its broader portfolio also includes plain, fluorescent, dyed and other functionalized particles.

Before ordering, record the full catalogue number and confirm the measured particle size, concentration, suspension medium, preservative and available batch documentation. Products with similar names can have different diameters and formulations.

For commercial development, ask whether the selected catalogue product can support the expected annual quantity, lot reservation and long-term supply requirements.

2. Bangs Laboratories

Bangs Laboratories manufactures microsphere products for diagnostics, biopharma, analytical instruments and life science research. Its product categories include carboxyl polystyrene, fluorescent carboxyl polystyrene, dyed carboxyl polystyrene and magnetic particles.

The company also publishes technical information about covalent coupling. Carboxyl groups can be activated with a carbodiimide such as EDC or EDAC to react with available primary amines on proteins and other biomolecules.

A published coupling procedure is a starting point rather than a guaranteed formulation. Antibody concentration, activation conditions, buffer, blocking and particle handling still require optimization for the intended assay.

Buyers should confirm the exact carboxyl level, particle concentration, additives, available quantity and product-use classification for the selected particle.

3. Spherotech

Spherotech supplies polystyrene particles with carboxyl and other functional groups. Its portfolio also includes fluorescent, colored, magnetic and biomolecule-coated beads, together with flow cytometry controls.

This range is useful when a project may require unconjugated particles during development and coated or fluorescent particles at a later stage.

Spherotech publicly lists products with defined size ranges, concentrations and package volumes. Buyers should determine whether a listed diameter represents a nominal value or a specified range.

Do not treat an unconjugated carboxyl particle, a protein-coated bead and an instrument-control bead as interchangeable products. Each is manufactured and documented for a different purpose.

4. PolyMicrospheres

PolyMicrospheres develops polymer microspheres for clinical diagnostic and related applications. Its carboxyl portfolio includes different surface designs rather than one universal carboxyl latex.

Available product families address factors such as residual surfactant, ligand accessibility, hydrophilicity, nonspecific binding and particle settling. These properties can affect coupling and completed-assay performance.

The highest carboxyl content does not automatically produce the best reagent. Excessive ligand loading or unsuitable surface properties can increase aggregation, steric interference or assay background.

Evaluate several candidate particles under the same coupling and assay conditions. Compare analytical performance as well as the amount of protein attached to the particles.

5. Magsphere

Magsphere supplies plain and surface-modified polystyrene particles, including carboxylated PS, colored carboxylated particles, fluorescent carboxylated particles and surfactant-free options.

Its product information describes emulsion and seeded-emulsion polymerization for producing spherical latex particles. The company also offers bulk-rate enquiries and custom synthesis for requirements outside standard catalogue products.

This makes Magsphere relevant to buyers comparing white latex, visibly colored labels and fluorescent formats from one supplier.

For a lateral flow project, test the particles after conjugation. Antibody loading, blocking and storage formulation can change particle aggregation, conjugate-pad release and membrane migration.

6. ACME Microspheres

ACME Microspheres offers polystyrene particles with carboxyl, amino and other functional groups for covalent coupling. Its portfolio includes standard and specialty carboxyl microspheres together with dyed, fluorescent and magnetic formats.

The company is particularly relevant when a diagnostic developer needs to compare different surface properties rather than selecting only by nominal particle size.

Low-surfactant, hydrophilic or other specialty surfaces may help address a specific formulation problem, but their suitability must be confirmed in the completed assay.

Ask for the specification of the exact product being considered, including diameter, size distribution, carboxyl content, solids concentration and suspension components.

7. Thermo Fisher Scientific

Thermo Fisher Scientific offers Invitrogen FluoSpheres carboxylate-modified microspheres. These are fluorescent polystyrene particles designed for laboratory applications such as microscopy, flow cytometry, cell tracing and research immunoassays.

This product family is relevant when the project needs both fluorescence and a carboxyl-containing surface. Individual products differ in particle diameter, fluorescence spectrum, solids concentration and package size.

Match the excitation and emission properties to the instrument rather than selecting by a general color description. Two particles described as green or red can require different optical settings.

Check the use classification of the selected catalogue number. Research products should not automatically be treated as qualified raw materials for commercial diagnostic manufacturing.

8. SANYU GROUP (SHBC)

SANYU GROUP supplies carboxyl polystyrene microspheres for immunoassay development, latex agglutination, particle-enhanced immunoturbidimetry, lateral flow and research applications.

The product range includes plain, colored and fluorescent carboxyl polystyrene microspheres. Standard products cover nano- and microscale sizes, with common solids concentrations selected according to particle diameter.

SANYU can review requirements for particle size, carboxyl content, concentration, color, fluorescence and packaging. The available specification and minimum evaluation quantity should be confirmed for each project.

For US enquiries, provide the intended application, required diameter, acceptable size distribution, surface-group requirement, quantity and delivery location. Batch documentation should be reviewed for the selected model rather than inferred from another particle size.

SANYU is an international manufacturing option serving American buyers. It should not be described as a US domestic manufacturer.

9. Lab261

Lab261 supplies polystyrene microspheres and nanoparticles in plain and functionalized formats, including carboxyl-containing particles.

Its broad size selection can be useful for projects outside conventional diagnostic latex ranges, including particle tracking, microfluidic research, cellular studies and environmental microplastic experiments.

A broad catalogue range does not mean that every diameter shares the same size tolerance, concentration or carboxyl level. Review the individual product specification before comparing it with another supplier.

Diagnostic developers should also confirm manufacturing controls, lot consistency, change notification and commercial production capability for the selected material.

10. Corpuscular

Corpuscular supplies carboxylated polystyrene nanospheres and microspheres through the Microspheres-Nanospheres product catalogue.

The broader catalogue includes multiple particle materials and surface chemistries. It can therefore be useful for research groups comparing polystyrene with other materials or searching for specialty particle sizes.

Buyers should confirm who manufactures the selected product, where it is manufactured and which specifications are controlled between batches.

For a commercial diagnostic project, also request information about production scale, quality documentation, supply continuity and any restrictions on the product’s intended use.

What Are Carboxyl Polystyrene Microspheres?

Carboxyl polystyrene microspheres are spherical polystyrene particles with carboxyl groups on or near their surfaces.

The polystyrene core provides the main particle structure. Surface carboxyl groups provide negative charge and reactive sites that can be used for covalent biomolecule immobilization.

Common names include:

• Carboxylated polystyrene microspheres

• Carboxyl polystyrene beads

• COOH polystyrene particles

• Carboxyl latex microspheres

• Carboxylate-modified polystyrene beads

• Functionalized PS microspheres

These terms can describe different formulations. Always confirm the polymer, functional group, particle size, concentration and suspension medium for the specific product.

How Carboxyl Microspheres Bind Antibodies

A common coupling method activates surface carboxyl groups with EDC, sometimes together with NHS or sulfo-NHS. Activated groups then react with available primary amines on an antibody or other biomolecule to form covalent amide bonds.

A general workflow includes:

1. Resuspend and wash the microspheres.

2. Transfer the particles into a suitable activation buffer.

3. Add the selected activation reagent.

4. Control activation time, pH and reagent concentration.

5. Add the antibody or other amine-containing ligand.

6. Allow the coupling reaction to proceed.

7. Quench remaining reactive groups.

8. Block the particle surface where required.

9. Wash and resuspend the conjugate.

10. Test binding activity, aggregation and storage stability.

The coupling process must be optimized for the selected particle and biomolecule. A high carboxyl value alone does not establish antibody activity, coupling efficiency or assay sensitivity.

Applications of Carboxyl Polystyrene Microspheres

Particle-Enhanced Immunoturbidimetric Assays

Antibodies can be immobilized on latex particles. When the target analyte produces particle agglutination, the resulting change in turbidity can be measured with a compatible clinical chemistry analyzer.

Particle diameter, surface chemistry, antibody loading and colloidal stability influence the analytical response. Candidate particles should be compared across the required measuring range.

Latex Agglutination Tests

Carboxylated particles can carry antibodies or antigens used in visible agglutination reactions. Particle size affects reaction behavior, settling and visual interpretation.

Colored particles may provide additional contrast, but color intensity does not replace evaluation of conjugation and assay specificity.

Lateral Flow Immunoassays

Colored or fluorescent carboxyl polystyrene microspheres can act as reporter labels in membrane-based assays.

Evaluate antibody coupling, conjugate-pad release, membrane migration, test-line signal, background and storage stability. A particle that looks strongly colored in a bottle may still migrate poorly after conjugation.

Flow Cytometry and Suspension Assays

Carboxylated particles can be conjugated with proteins, antibodies or oligonucleotides for research assays and particle-based analysis.

If the beads are intended as instrument standards, confirm whether they have the required assigned values or traceability. Generic carboxylated particles are not automatically calibration standards.

Research and Particle Studies

Carboxyl PS particles are also used in cellular uptake studies, surface-modification research, biosensors and microfluidic experiments.

Review the suspension additives and preservative before biological use. Components acceptable for an in-vitro particle assay may interfere with cell-based experiments.

How to Compare Products from Different Suppliers

Particle Diameter

Request the nominal diameter, measured result and measurement method.

Dynamic light scattering reports hydrodynamic behavior in suspension, while microscopy examines particle dimensions more directly. Results obtained by different methods should not be treated as identical.

Size Distribution

A nominal diameter does not describe the complete distribution. Ask whether the supplier reports CV, PDI, standard deviation or another distribution measurement.

CV and DLS PDI represent different calculations and should not be used as interchangeable values.

Carboxyl Content

Carboxyl content may be reported in μmol/g, μeq/g, meq/g or another format. Check both the unit and the test method before comparing values.

More surface carboxyl groups provide additional potential reaction sites, but the highest value may not give the best functional assay result.

Solids Concentration

Confirm whether concentration is expressed as weight per volume, weight per weight or particle count.

For example, a 10% w/v suspension contains 100 mg of particle solids per milliliter. Bottle volume alone does not show the amount of particle material supplied.

Suspension Formulation

Ask about the dispersion medium, surfactant, preservative, pH and any other additives relevant to the experiment.

These components can affect EDC activation, antibody activity, cell compatibility, membrane migration and storage stability.

Batch Consistency

For repeated production, identify which properties are controlled between batches. Relevant items may include diameter, distribution, carboxyl content, concentration and pH.

Application performance still requires customer validation because a COA cannot cover every antibody, buffer and assay format.

Documentation and Scale-Up

Confirm which documents are available for the selected product and batch. These may include a specification sheet, COA and SDS.

Commercial buyers should also discuss sample quantity, pilot supply, production quantity, lead time, lot reservation and manufacturing-change notification.

Ordering for Delivery to the USA

Request a written quotation for the exact model, concentration, quantity and receiving address.

The quotation should distinguish product price from freight and other applicable shipment costs. For international supply, confirm the delivery route, packaging and estimated transit time.

The receiving organization should review its own import, documentation and product-use requirements. These requirements may differ between a research laboratory, distributor and diagnostic manufacturer.

Before approving a larger order, evaluate representative material under the actual coupling and assay conditions. Retain the product model, batch number, preparation method and test results for future comparison.

Information to Include in an RFQ

A useful request for quotation should include:

• Intended application

• Required particle diameter

• Acceptable size distribution

• Required carboxyl content, if known

• Plain, colored or fluorescent format

• Required solids concentration

• Suspension-medium requirements

• Surfactant or preservative restrictions

• Sample quantity

• Expected production quantity

• Required documentation

• Research or diagnostic-development use

• Delivery city, state and ZIP code

• Required delivery date

• Custom packaging or labeling requirements

If the final particle specification has not been established, provide the assay format and the main performance problem. This gives the supplier enough information to recommend a manageable set of candidates.

Frequently Asked Questions

Are All Ten Companies US Manufacturers?

No. The list includes US-based companies, major suppliers and international manufacturers serving US buyers. Confirm the manufacturing location of the selected product when domestic production is required.

What Is the Best Particle Size for an Immunoturbidimetric Assay?

There is no universal best size. The preferred diameter depends on the analyte, antibody, analyzer, required sensitivity and measuring range. Compare candidate particles in the completed assay.

Can Carboxyl Polystyrene Microspheres Bind Antibodies?

Yes. Surface carboxyl groups can be activated for covalent reaction with available primary amines on antibodies. Coupling conditions and final antibody activity require experimental optimization.

Is EDC/NHS Coupling Always Required?

No. EDC alone can be used in some protocols, while NHS or sulfo-NHS may be added to modify the activation process. The selected chemistry should match the particle, biomolecule and experimental conditions.

Does Higher Carboxyl Content Mean Better Assay Performance?

Not necessarily. Carboxyl content affects potential coupling sites, but excessive loading, aggregation, steric effects and nonspecific binding can reduce functional performance.

Are Carboxyl PS Microspheres Magnetic?

Standard carboxyl polystyrene microspheres are not necessarily magnetic. Select a product specifically identified as magnetic when magnetic separation is required.

Should I Compare Prices by Bottle Volume?

No. Compare the particle concentration and total amount of solids in each package. Equal bottle volumes can contain different quantities of polystyrene.

Should I Request a COA Before Buying?

Yes, request the available specification and representative or batch-specific documentation. The COA should be reviewed together with sample-testing results because it may not include application-specific performance.

Can an International Manufacturer Supply US Customers?

Yes, subject to the product, destination and available shipping route. Confirm freight, documentation, delivery time and receiving requirements before payment.

Conclusion

The US market is served by domestic microsphere manufacturers, research-product companies and international suppliers. Each company offers a different combination of catalogue availability, surface chemistry, technical support and commercial supply.

Select the exact particle according to diameter, size distribution, carboxyl content, solids concentration and formulation. For diagnostic development, also evaluate lot consistency, documentation, scale-up capability and the completed assay result.

SANYU GROUP supplies plain, colored and fluorescent carboxyl polystyrene microspheres for immunoassay, lateral flow and research projects. Provide the application, required particle size, concentration, quantity and US delivery location when requesting a product recommendation.