2.8um NHS Magnetic Beads MagNHS2.8UM-10 5%

2.8µm NHS Magnetic Beads for Immunoassay Research

SHBC MNHS2.8UM-10 NHS Magnetic Beads are 2.8µm magnetic particles with an NHS-activated surface.

They are designed for direct coupling of antibodies, antigens, proteins, peptides and other amine-containing molecules.

The product is supplied at 5% solids for immunoassay research, magnetic separation, affinity capture and bulk reagent production.

Product: 2.8µm NHS Magnetic Beads
Catalog Number: MNHS2.8UM-10
Brand: SHBC
Manufacturer: Shanghai SanYu Biotechnology Co., Ltd.
Particle Size: 2.8µm
Surface: NHS activated
Solids Content: 5%
Main Application: Immunoassay research
Supply: Samples, pilot batches and bulk production
Intended Use: Research use only

Product Overview

MNHS2.8UM-10 provides a ready-to-couple magnetic surface.

The NHS groups react with primary amino groups on antibodies and proteins.

The reaction forms stable covalent amide bonds.

No additional EDC/NHS activation is normally required before coupling.

The 2.8µm particle size provides a practical balance between:

• Magnetic response

• Surface area

• Particle recovery

• Suspension stability

• Repeated washing

• Automated processing

The magnetic format simplifies separation of bound and unbound reagents.

Technical Specifications

The following data should be confirmed by the final TDS or lot-specific COA:

• Actual particle-size range

• Particle-size CV

• Particle morphology

• Magnetic material

• Magnetic content

• Magnetic response time

• NHS-group density

• Antibody coupling capacity

• Protein coupling capacity

• Particle concentration

• Suspension buffer

• Preservative

• Package size

• Shelf life

• Storage temperature

The 5% solids content alone cannot determine antibody coupling capacity or magnetic response time.

Key Advantages

Ready-to-Couple NHS Surface

The surface is already NHS activated.

No separate bead-activation step is normally required.

This reduces:

• Activation reagents

• Preparation time

• Intermediate washing

• Process variation

• Operator workload

Direct Antibody Coupling

Antibodies containing accessible primary amino groups can react directly with the NHS surface.

The coupling process is simple and suitable for immunoassay reagent development.

Stable Covalent Bond

NHS esters react with primary amines to form stable amide bonds.

Covalent immobilization helps reduce ligand loss during washing, incubation and storage.

2.8µm Particle Size

The 2.8µm size provides a larger surface per particle than smaller magnetic beads.

It may also support easier magnetic recovery and repeated washing.

Magnetic Separation

The beads can be collected using an external magnetic field.

This supports:

• Fast washing

• Buffer exchange

• Removal of unbound reagents

• Target enrichment

• Automated processing

Good Resuspension Potential

Uniform resuspension is important for consistent bead dispensing and assay precision.

The actual performance must be validated in the final SHBC formulation.

Suitable for Automation

MNHS2.8UM-10 can be evaluated in manual, semi-automated and automated immunoassay workflows.

Automation testing should include:

• Bead aspiration

• Dispensing accuracy

• Magnetic collection

• Washing efficiency

• Redispersion

• Carryover

5% Solids Content

The concentrated suspension supports:

• Laboratory evaluation

• Coupling-process optimization

• Pilot production

• Bulk reagent preparation

Bulk Manufacturing

SHBC supports:

• Research samples

• Pilot batches

• Repeat orders

• OEM production

• Private-label packaging

• Enterprise bulk supply

How NHS Coupling Works

NHS esters mainly react with primary amino groups.

Primary amino groups are present on:

• Lysine residues

• Protein N-termini

• Peptide N-termini

• Amino-modified oligonucleotides

• Amino-modified ligands

The simplified reaction is:

NHS Magnetic Bead + Amine-Containing Ligand → Covalently Coupled Bead–Ligand

The coupling forms a stable amide linkage.

Use an Amine-Free Buffer

Use a coupling buffer without competing primary amines.

Avoid during coupling:

• Tris

• Glycine

• Ethanolamine

• Free amino acids

• Amine-containing stabilizers

These substances can react with NHS groups and reduce ligand coupling.

Official NHS magnetic bead protocols similarly recommend coupling proteins in an amine-free buffer and quenching the remaining active groups after coupling.

Control NHS Hydrolysis

NHS groups can hydrolyze in aqueous solution.

Prepare the beads immediately before coupling.

Do not leave the activated beads in aqueous coupling buffer longer than necessary.

Quench Remaining NHS Groups

After ligand coupling, remaining NHS groups should be quenched.

This helps reduce:

• Unwanted surface reactions

• Non-specific binding

• Assay background

• Batch variation

Immunoassay Applications

Magnetic Sandwich Immunoassays

Couple a capture antibody to MNHS2.8UM-10.

The antibody-coated beads capture the target antigen.

A labeled detection antibody generates the assay signal.

Potential research targets include:

• Hormones

• Cytokines

• Tumor biomarkers

• Cardiac biomarkers

• Inflammatory markers

• Infectious-disease antigens

• Autoantibodies

• Veterinary biomarkers

Chemiluminescent Immunoassays

MNHS2.8UM-10 can be evaluated as a magnetic solid phase in CLIA and CLEIA development.

The beads support:

• Target capture

• Magnetic separation

• Repeated washing

• Reporter binding

• Substrate reaction

• Luminescence detection

Fluorescent Immunoassays

The magnetic beads can be combined with fluorescent detection antibodies or probes.

Enzyme Immunoassays

The beads may be used with enzyme-labeled detection reagents and compatible substrates.

Competitive Immunoassays

Potential applications include:

• Drugs

• Haptens

• Hormones

• Toxins

• Metabolites

• Small molecules

• Peptides

Antigen-Coated Magnetic Beads

Antigens and recombinant proteins may be coupled for:

• Antibody detection

• Serological research

• Autoantibody studies

• Vaccine-response research

• Antibody screening

Affinity Capture

Antibody- or protein-coated beads may be used for:

• Target enrichment

• Immunoprecipitation research

• Protein purification research

• Antigen capture

• Protein interaction studies

NHS magnetic beads are also used for covalent immobilization of free-amine-containing biomolecules in pull-down and protein-enrichment workflows.

Suitable Coupling Molecules

MNHS2.8UM-10 may be evaluated with:

• Monoclonal antibodies

• Polyclonal antibodies

• Recombinant antibodies

• Antibody fragments

• Antigens

• Recombinant proteins

• Peptides

• Enzymes

• Lectins

• Receptors

• Amino-modified oligonucleotides

• Amino-modified aptamers

• Amine-containing synthetic ligands

The molecule must contain an accessible primary amino group.

Recommended Coupling Workflow

1. Resuspend the Beads

Mix MNHS2.8UM-10 until homogeneous.

Avoid excessive foaming.

2. Transfer the Required Amount

Calculate the bead amount according to:

• Number of tests

• Beads per test

• Required capture capacity

• Reaction volume

• Expected processing loss

3. Magnetically Collect the Beads

Place the tube in a compatible magnetic separator.

Wait until the beads are collected.

Remove the storage solution.

4. Wash with Coupling Buffer

Use a validated amine-free buffer.

Avoid Tris and glycine.

5. Prepare the Ligand

Transfer the antibody or protein into the coupling buffer.

Remove incompatible components when necessary.

Potential interfering components include:

• Tris

• Glycine

• Carrier proteins

• Free amino acids

• Amine-containing stabilizers

6. Add the Ligand

Add the antibody or protein to the prepared NHS magnetic beads.

Mix immediately.

7. Incubate

Maintain gentle mixing.

Optimize:

• Ligand concentration

• Bead concentration

• Buffer pH

• Reaction time

• Temperature

• Mixing speed

8. Wash the Coupled Beads

Magnetically collect the beads.

Remove unbound ligand.

Wash with a compatible buffer.

9. Quench Remaining NHS Groups

Use a validated quenching reagent.

Evaluate the effect on background and ligand activity.

10. Block and Formulate

Add a suitable blocking and storage formulation.

Evaluate:

• Particle dispersion

• Magnetic response

• Antibody activity

• Non-specific binding

• Storage stability

Magnetic Immunoassay Workflow

1. Couple the capture antibody.

2. Quench remaining NHS groups.

3. Block and formulate the beads.

4. Add the test sample.

5. Incubate for target capture.

6. Magnetically collect the beads.

7. Wash away unbound sample.

8. Add the labeled detection antibody.

9. Incubate again.

10. Perform final magnetic washing.

11. Add the detection substrate.

12. Measure the signal.

Possible detection methods include:

• Chemiluminescence

• Electrochemiluminescence

• Fluorescence

• Enzyme colorimetry

• Other compatible reporter systems

Why Choose 2.8µm Magnetic Beads?

Easier Magnetic Recovery

The 2.8µm size may provide easier magnetic collection than smaller particles under comparable conditions.

Actual collection time depends on:

• Magnetic material content

• Magnet strength

• Sample volume

• Liquid height

• Sample viscosity

• Vessel geometry

Larger Surface per Particle

Each 2.8µm bead provides more physical surface than each 1.5µm or 200nm bead.

Practical Repeated Washing

The larger particle size may support a more visible and compact magnetic bead pellet.

This can be useful in repeated washing processes.

Good Automation Positioning

Uniform 2.8µm superparamagnetic beads are widely used in automated magnetic workflows because they combine liquid-phase handling, magnetic separation and reproducible processing.

Particle-Size Comparison

The final particle size should be selected through direct immunoassay testing.

NHS Magnetic Beads vs Carboxyl Magnetic Beads

Choose NHS beads when rapid direct protein coupling is preferred.

Choose carboxyl beads when a validated EDC/NHS activation process is already available.

Quality Control

Recommended quality-control items include:

• Mean particle diameter

• Particle-size range

• Particle-size CV

• Particle morphology

• Suspension appearance

• Solids content

• NHS activity

• Magnetic response

• Magnetic recovery

• Redispersion

• Aggregate level

• Antibody coupling capacity

• Functional target binding

• Non-specific binding

• Batch consistency

Coupling Efficiency

Possible evaluation methods include:

• Protein mass balance

• Fluorescent ligand measurement

• Surface NHS activity testing

• Functional target-binding assays

Protein uptake does not always equal active antibody loading.

Functional immunoassay testing is essential.

Magnetic Performance

Evaluate:

• Magnetic collection time

• Bead recovery

• Residual beads in the supernatant

• Redispersion after collection

• Performance in the intended reaction vessel

• Compatibility with the intended analyzer

Bulk Manufacturing and Customization

Shanghai SanYu Biotechnology Co., Ltd. supports:

• Research samples

• Pilot batches

• Bulk manufacturing

• OEM production

• Private-label packaging

• Custom package sizes

• Custom NHS density

• Custom solids concentration

• Custom magnetic response

• Customer-specific quality standards

For project evaluation, provide:

• Required quantity

• Annual demand

• Intended immunoassay

• Ligand type

• Required coupling capacity

• Bead amount per test

• Magnetic separator or analyzer

• Preferred package size

• Buffer restrictions

• Preservative restrictions

• Quality-control requirements

Handling and Storage

Follow the final SHBC product label, TDS and lot-specific COA.

General recommendations:

• Store under the specified refrigerated conditions.

• Do not freeze unless validated.

• Keep the container tightly closed.

• Mix before sampling.

• Do not allow the beads to dry.

• Use clean, low-binding tubes.

• Avoid amine-containing buffers before coupling.

• Protect NHS groups from hydrolysis.

• Use prepared beads promptly.

• Do not return diluted material to the original bottle.

Frequently Asked Questions

What is MNHS2.8UM-10?

MNHS2.8UM-10 is a 2.8µm NHS-activated magnetic bead suspension supplied at 5% solids.

What is the main application?

It is designed for antibody and protein coupling in immunoassay research.

Is EDC/NHS activation required?

No additional EDC/NHS activation is normally required.

The bead surface is already NHS activated.

Which molecules can be coupled?

Antibodies, antigens, proteins, peptides, enzymes and other amine-containing molecules may be evaluated.

Which groups react with NHS?

NHS esters mainly react with primary amino groups.

Which buffers should be avoided?

Avoid Tris, glycine and other amine-containing buffers during coupling.

Is quenching required?

Quenching remaining NHS groups is generally recommended after ligand coupling.

Can MNHS2.8UM-10 be used in CLIA research?

Yes. It can be evaluated as a magnetic solid phase in chemiluminescent immunoassay development.

Can it be used on automated analyzers?

Yes, subject to validation of dispensing, magnetic collection, washing and redispersion.

What is the antibody coupling capacity?

Use the final product specification or lot-specific COA.

Do not estimate it from solids content alone.

How are the beads separated?

Use an external magnetic separator compatible with the reaction vessel and sample volume.

Can the beads be frozen?

Freezing is generally not recommended unless validated.

Can the bead pellet be allowed to dry?

No. Drying may cause aggregation and poor redispersion.

Is bulk production available?

Yes. SHBC supports samples, pilot batches, OEM projects and enterprise bulk manufacturing.

Request a Sample or Quotation

SHBC MNHS2.8UM-10 provides:

• 2.8µm nominal particle size

• NHS-activated surface

• 5% solids content

• Direct amine-based coupling

• Stable covalent ligand attachment

• Magnetic separation

• Immunoassay compatibility

• Automation-development potential

• Sample and bulk supply

• OEM and customization support

Product Name: 2.8µm NHS Magnetic Beads
Catalog Number: MNHS2.8UM-10
Brand: SHBC
Manufacturer: Shanghai SanYu Biotechnology Co., Ltd.
Particle Size: 2.8µm
Surface: NHS activated
Solids Content: 5%
Application: Immunoassay research
Supply: Samples, pilot batches and bulk production
Intended Use: Research Use Only. Not for diagnostic or therapeutic use.