50 um Carboxyl Crosslinked PS/DVB Microspheres CPS/DVB50UM 10%

50 μm Carboxyl Crosslinked PS/DVB Microspheres CPS/DVB50UM

SHBC CPS/DVB50UM Carboxyl Crosslinked PS/DVB Microspheres are 50 μm functional polymer microspheres with a crosslinked polystyrene/divinylbenzene matrix and reactive surface carboxyl groups.

Supplied at 10% solids, CPS/DVB50UM is designed for antibody coupling, protein immobilization, bead-based immunoassay development and custom functional microsphere production.

The large 50 μm particle format provides convenient particle recovery, washing and handling for research and scalable production workflows.

CPS/DVB50UM Technical Specifications

Crosslinked PS/DVB Structure

CPS/DVB50UM uses divinylbenzene to crosslink the polystyrene matrix.

DVB crosslinking creates a more rigid polymer network and is commonly used for larger polystyrene microspheres when greater structural stability is required. Polysciences states that its polystyrene microspheres of 4.5 μm and larger are crosslinked with divinylbenzene.

Potential advantages include:

• Good particle rigidity

• Stable spherical morphology

• Improved structural stability

• Convenient repeated washing

• Reliable particle recovery

• Suitable surface functionalization

Carboxyl Surface for Covalent Coupling

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

Typical coupling chemistry:

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

Carboxyl polystyrene microspheres are widely used for covalent attachment of proteins, peptides and amino-functional molecules through carbodiimide-mediated coupling.

Key Advantages of CPS/DVB50UM

• 50 μm particle size

• High 10% solid content

• Crosslinked PS/DVB matrix

• Reactive carboxyl surface

• Suitable for EDC/NHS coupling

• Stable covalent ligand immobilization

• Easy particle recovery

• Convenient centrifugation and washing

• Suitable for antibody and antigen coupling

• Suitable for research and bulk production

Why Choose 50 μm Carboxyl Microspheres?

The 50 μm particle format is designed for applications where convenient handling and easy particle recovery are important.

Potential benefits include:

• Fast sedimentation

• Convenient centrifugation

• Easy washing

• Straightforward resuspension

• Reduced particle loss during processing

• Convenient batch coupling

• Easy visual observation of particles

• Suitable for larger functional solid phases

Larger particles provide easier physical handling, while smaller particles provide more total surface area per unit mass. Particle size should therefore be selected according to ligand capacity, assay kinetics and handling requirements. Spherotech's particle calculations likewise show total surface area decreasing as particle diameter increases.

Immunoassay Applications

Antibody-Coupled Microspheres

Capture antibodies can be covalently immobilized on CPS/DVB50UM for:

• Bead-based immunoassays

• Antigen detection

• Biomarker detection

• Serological assay development

• Pathogen-detection research

• Custom diagnostic reagent development

Covalent attachment is useful when stable antibody retention is required during repeated washing and storage.

Antigen-Coupled Microspheres

Antigens can be immobilized for:

• Antibody detection

• Serological research

• Autoantibody assay development

• Infectious-disease research

• Assay development

• Method validation

Protein and Biomolecule Applications

CPS/DVB50UM can also be evaluated for:

• Protein immobilization

• Enzyme immobilization

• Peptide coupling

• Affinity ligand preparation

• Biomolecule capture

• Biosensor development

• Surface chemistry research

• Oligonucleotide immobilization

• Custom functional particle preparation

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 coupling efficiency depends on ligand purity, concentration and reaction conditions.

General EDC/NHS Coupling Workflow

1. Resuspend the Microspheres

Mix CPS/DVB50UM thoroughly before sampling.

Because 50 μm particles settle relatively quickly, resuspend the suspension immediately before use.

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 purified 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 to form stable amide bonds.

6. Block Residual Reactive Sites

Use a suitable blocking or quenching reagent after coupling.

7. Wash and Resuspend

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

Bangs Laboratories specifically describes EDAC-mediated coupling for immobilizing amine-terminated proteins, DNA and other molecules on carboxyl-functionalized PS and PS/DVB microspheres.

Factors Affecting Coupling Efficiency

Important optimization parameters include:

• Microsphere concentration

• Ligand concentration

• EDC concentration

• NHS concentration

• Activation pH

• Coupling-buffer composition

• Reaction temperature

• Incubation time

• Mixing efficiency

• Blocking conditions

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

Immunoassay Development Tips

For consistent assay performance:

• Use purified antibodies or antigens.

• Avoid unnecessary carrier proteins during activation.

• Resuspend particles before sampling.

• Keep particles mixed during coupling.

• Optimize EDC/NHS concentration.

• Control activation pH.

• Optimize ligand loading.

• Block residual reactive sites.

• Evaluate nonspecific binding.

• Test coupled-particle storage stability.

CPS/DVB50UM vs. Smaller Carboxyl Microspheres

The preferred particle size depends on assay design, required ligand loading and detection method.

Crosslinked PS/DVB vs. Standard PS Microspheres

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

Covalent Coupling vs. Passive Adsorption

Quality Control for Bulk Production

For immunoassay reagent development, recommended evaluation items include:

• 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 reproducibility

Why Choose SHBC CPS/DVB50UM?

• 50 μm carboxyl crosslinked PS/DVB microspheres

• High 10% solid-content suspension

• Reactive COOH surface

• Suitable for EDC/NHS coupling

• Designed for antibody and protein immobilization

• Suitable for immunoassay development

• Samples available for evaluation

• Stable batch manufacturing

• Bulk production capability

• Custom quantity and packaging support

Storage and Handling

Recommended practices include:

• Keep the container tightly sealed.

• Mix thoroughly before sampling.

• Resuspend settled particles before use.

• Avoid unnecessary freezing.

• Prevent microbial contamination.

• Use clean pipettes and containers.

• Avoid conditions causing irreversible aggregation.

• Validate storage conditions after biomolecule coupling.

Frequently Asked Questions

What is CPS/DVB50UM?

CPS/DVB50UM is a 50 μm carboxyl-functional crosslinked polystyrene/divinylbenzene microsphere product supplied at 10% solids.

What does PS/DVB mean?

PS/DVB means polystyrene crosslinked with divinylbenzene.

Why use DVB crosslinking?

DVB creates a more rigid polymer network and helps maintain structural stability in 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/DVB50UM?

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

Can CPS/DVB50UM be used for immunoassays?

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

What is the solid content?

CPS/DVB50UM 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 50 μm instead of smaller microspheres?

50 μm particles provide easier handling, sedimentation and recovery. Smaller microspheres generally provide greater surface area per unit mass.

Do 50 μm microspheres require mixing?

Yes. Larger particles settle faster, so periodic or continuous mixing is recommended during coupling and assay reactions.

Can 50 μm microspheres be used in flow cytometry?

Instrument compatibility should be confirmed before use because many flow cytometers have particle-size limits. The product is better positioned primarily for large-particle bead assays and biomolecule immobilization unless the intended instrument has been validated.

Is coupling optimization necessary?

Yes. EDC/NHS concentration, activation 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/DVB50UM Samples

Contact Shanghai SanYu Biotechnology Co., Ltd. for CPS/DVB50UM 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/DVB50UM is supplied for research and process development. Final diagnostic applications should be validated by the customer.