20um Carboxyl Crosslinked PS/DVB Microspheres CPS/DVB20UM 10%

20 μm Carboxyl Crosslinked PS/DVB Microspheres CPS/DVB20UM

SHBC CPS/DVB20UM Carboxyl Crosslinked PS/DVB Microspheres are 20 μm functional polymer microspheres with a crosslinked polystyrene/divinylbenzene matrix and surface carboxyl groups.

Supplied at 10% solids, CPS/DVB20UM is designed for antibody coupling, protein immobilization, bead-based immunoassays and scalable reagent development.

CPS/DVB20UM Technical Specifications

Crosslinked PS/DVB Structure

CPS/DVB20UM uses divinylbenzene to crosslink the polystyrene matrix.

DVB crosslinking creates a more rigid polymer network and is commonly used in larger polystyrene microspheres to improve structural stability. Polysciences states that its PS microspheres of 4.5 μm and larger are crosslinked with divinylbenzene.

Key benefits include:

• Good particle rigidity

• Stable spherical structure

• Improved mechanical stability

• Suitable for repeated washing

• Reliable particle handling

• Suitable for surface functionalization

Carboxyl Surface for Covalent Coupling

Surface carboxyl groups provide reactive sites for covalent immobilization of biomolecules.

Typical chemistry:

COOH Surface → EDC/NHS Activation → Amine-Containing Biomolecule → Stable Amide Bond

Suitable biomolecules include:

• Antibodies

• Antigens

• Recombinant proteins

• Peptides

• Enzymes

• Amino-modified oligonucleotides

• Other amine-containing ligands

Bangs Laboratories specifically recommends EDAC/EDC-mediated coupling for attaching amine-terminated proteins, DNA and other molecules to carboxyl-functionalized PS and PS/DVB microspheres.

Key Advantages of CPS/DVB20UM

• 20 μm particle size

• High 10% solid content

• Crosslinked PS/DVB matrix

• Reactive carboxyl surface

• Suitable for EDC/NHS coupling

• Stable covalent ligand attachment

• Convenient washing and separation

• Suitable for antibodies and proteins

• Suitable for bead-based immunoassays

• Available for bulk production

Why Choose 20 μm Microspheres?

The 20 μm particle format is suitable for applications requiring straightforward particle handling and larger functional solid phases.

Potential advantages include:

• Easy centrifugation

• Convenient washing

• Easy visual monitoring of particle sedimentation

• Straightforward resuspension

• Suitable for larger bead-based assay formats

• Convenient laboratory and production handling

Spherotech currently offers crosslinked carboxyl polystyrene particles in the 18.0–24.9 μm range, directly supporting this size class for functionalized microsphere applications.

Immunoassay Applications

Antibody-Coupled Microspheres

Capture antibodies can be covalently immobilized on CPS/DVB20UM for:

• Bead-based immunoassays

• Antigen detection

• Biomarker detection

• Serological assay development

• Diagnostic reagent research

• Custom particle-based assays

Covalent immobilization can provide more stable ligand retention than simple passive adsorption during repeated washing.

Antigen-Coupled Microspheres

Antigens can be immobilized for:

• Antibody detection

• Serology research

• Autoantibody assay development

• Infectious-disease research

• Assay calibration

• Method development

Flow Cytometry and Particle-Based Assays

CPS/DVB20UM may also be evaluated in suitable particle-based analytical systems.

Potential applications include:

• Antibody-binding studies

• Antigen detection

• Biomolecule-binding assays

• Multiplex assay research

• Particle reference studies

Instrument compatibility should be confirmed because some flow cytometers have particle-size limitations.

Protein and Biomolecule Applications

CPS/DVB20UM can also be evaluated for:

• Protein immobilization

• Enzyme immobilization

• Peptide coupling

• Affinity ligand preparation

• Biomolecule capture

• Biosensor development

• Surface chemistry research

• Amino-modified oligonucleotide coupling

Suitable Coupling Molecules

The carboxyl-functional surface can be evaluated with:

• Monoclonal antibodies

• Polyclonal antibodies

• Recombinant proteins

• Diagnostic antigens

• Peptides

• Enzymes

• Amino-modified DNA

• Amino-modified RNA

• Other amine-containing ligands

Final performance depends on ligand purity, concentration and coupling conditions.

General EDC/NHS Coupling Workflow

1. Resuspend the Microspheres

Mix CPS/DVB20UM thoroughly before sampling.

2. Wash the Microspheres

Wash the particles using a suitable activation buffer.

3. Activate Carboxyl Groups

Add EDC with or without NHS to activate surface carboxyl groups.

4. Add the Biomolecule

Add the antibody, antigen, protein or other amine-containing ligand.

5. Perform Covalent Coupling

Allow activated carboxyl groups to react with primary amino groups on the biomolecule.

6. Block Residual Reactive Sites

Use a suitable blocking or quenching reagent.

7. Wash and Resuspend

Remove unbound biomolecules and coupling reagents, then resuspend the functionalized microspheres in the selected assay or storage buffer.

Factors Affecting Coupling Efficiency

Important optimization factors include:

• Microsphere concentration

• Ligand concentration

• EDC concentration

• NHS concentration

• Activation pH

• Coupling-buffer composition

• Reaction time

• Reaction temperature

• Mixing efficiency

• Blocking conditions

Small-scale optimization is recommended before production scale-up.

Crosslinked PS/DVB vs. Standard PS Microspheres

Crosslinked PS/DVB is suitable when both particle stability and reactive surface chemistry are required.

Covalent Coupling vs. Passive Adsorption

Quality Control for Bulk Production

For immunoassay reagent development, evaluate:

• Particle-size consistency

• Suspension uniformity

• Solid-content consistency

• Surface carboxyl functionality

• Coupling efficiency

• Ligand loading

• Nonspecific binding

• Signal-to-background ratio

• Assay sensitivity

• Storage stability

• Batch-to-batch consistency

Why Choose SHBC CPS/DVB20UM?

• 20 μm carboxyl crosslinked PS/DVB microspheres

• High 10% solid content

• Functional COOH surface

• Suitable for EDC/NHS coupling

• Designed for antibody and protein immobilization

• Suitable for immunoassay research

• Sample evaluation available

• Stable batch production

• Bulk manufacturing capability

• Research and production quantities available

Storage and Handling

Recommended practices include:

• Keep the container tightly sealed.

• Mix thoroughly before sampling.

• Prevent microbial contamination.

• Avoid unnecessary freezing.

• Use clean pipettes and containers.

• Avoid conditions causing irreversible aggregation.

• Validate storage conditions after biomolecule coupling.

Frequently Asked Questions

What is CPS/DVB20UM?

CPS/DVB20UM is a 20 μm carboxyl-functional crosslinked PS/DVB microsphere product supplied at 10% solids.

What does PS/DVB mean?

PS/DVB refers to polystyrene crosslinked with divinylbenzene.

Why use DVB crosslinking?

DVB creates a more rigid polymer network and improves the structural stability of larger polystyrene microspheres.

What is the function of the carboxyl surface?

Surface carboxyl groups provide reactive sites for covalent attachment of antibodies, proteins and other amine-containing biomolecules.

Can antibodies be coupled to CPS/DVB20UM?

Yes. Antibodies can be immobilized using optimized EDC or EDC/NHS coupling chemistry.

Can CPS/DVB20UM be used for immunoassays?

Yes. It can be evaluated for bead-based antigen, antibody and biomarker detection.

What is the solid content?

CPS/DVB20UM is supplied at 10% solids.

Can amino-modified oligonucleotides be coupled?

Yes. Amino-modified DNA or RNA can be evaluated for carbodiimide-mediated coupling to the carboxyl surface.

Why choose 20 μm instead of smaller microspheres?

20 μm particles provide easier handling and recovery, while smaller particles generally provide greater surface area per unit mass. The best size depends on assay format and required binding capacity.

Is coupling optimization required?

Yes. EDC/NHS concentration, pH, ligand loading, reaction time and blocking conditions should be optimized for each project.

Can SHBC supply bulk quantities?

Yes. SHBC supports sample evaluation and bulk supply for immunoassay developers, biotechnology companies and research organizations.

Request CPS/DVB20UM Samples

Contact Shanghai SanYu Biotechnology Co., Ltd. for CPS/DVB20UM samples, technical documentation and bulk quotations.

Please provide:

• Target antibody or protein

• Assay format

• Coupling chemistry

• Required microsphere quantity

• Target application

• Development stage

• Estimated annual demand

CPS/DVB20UM is supplied for research and process development. Final diagnostic applications should be validated by the customer.