2µm Amino Magnetic Beads MNH2UM-10 5%

2µm Amino Magnetic Beads MNH2UM-10

MNH2UM-10 is a 2µm amino-functional magnetic bead suspension supplied at a solids content of 5% w/v, equivalent to 50mg/mL.

The product is developed for antibody, antigen, protein, peptide and enzyme immobilization in magnetic immunoassay research, reagent formulation, process development, pilot-scale validation and batch production.

Amino groups on the bead surface provide reactive sites for covalent biomolecule immobilization through an appropriate crosslinking system. After coupling, the functionalized magnetic beads can be used as a solid-phase carrier for target capture, magnetic separation, washing and signal detection.

MNH2UM-10 is intended for biotechnology companies, diagnostic reagent developers, research institutions and immunoassay manufacturers requiring concentrated amino magnetic beads for projects progressing from laboratory evaluation to bulk manufacturing.

Product Overview

MNH2UM-10 combines a 2µm nominal particle size with a concentrated 5% solids formulation.

The 2µm particle format can be evaluated for immunoassays that require a balance between available particle surface, suspension behavior, magnetic collection and repeated washing.

The amino-functional surface enables developers to select a coupling strategy based on the available functional groups of the target biomolecule. Potential coupling targets include monoclonal antibodies, polyclonal antibodies, antigens, recombinant proteins, enzymes, peptides and suitably modified oligonucleotides.

After ligand immobilization, the bead conjugate may be incorporated into magnetic immunoassays, chemiluminescence immunoassays, electrochemiluminescence research, immunomagnetic separation and other particle-based analytical systems.

The final coupling conditions and assay formulation should be optimized according to the selected ligand, sample matrix, magnetic separator, detection chemistry and instrument platform.

MNH2UM-10 Product Specifications

Final release specifications should be confirmed using the corresponding technical data sheet, certificate of analysis and lot-specific quality documentation.

Key Features of 2µm Amino Magnetic Beads

2µm Particle Format

The 2µm particle size provides an intermediate format between nanoscale magnetic particles and larger magnetic microspheres.

It can be evaluated when an assay requires practical magnetic collection while retaining sufficient particle numbers and available surface for biomolecule immobilization.

Actual separation performance depends on several factors, including:

• Magnetic content;

• Particle-size distribution;

• Bead concentration;

• Sample viscosity;

• Reaction-vessel geometry;

• Magnet strength;

• Magnet position;

• Collection time.

Amino-Functional Surface

Primary amino groups on the bead surface provide reactive sites for further chemical modification.

An appropriate crosslinker can connect the bead amino groups with compatible groups on antibodies, proteins, peptides or other biological ligands.

The selected coupling route should be based on:

• Ligand structure;

• Available functional groups;

• Required conjugate orientation;

• Desired bond stability;

• Sensitivity of the biomolecule;

• Intended immunoassay format.

5% Solids Content

MNH2UM-10 is supplied at 5% w/v, equivalent to 50mg/mL.

The concentrated suspension allows developers to prepare multiple working concentrations during:

• Coupling-process screening;

• Ligand-loading optimization;

• Blocking studies;

• Immunoassay formulation;

• Pilot production;

• Stability evaluation;

• Manufacturing scale-up.

For example:

• 20µL contains approximately 1mg of magnetic beads;

• 100µL contains approximately 5mg;

• 1mL contains approximately 50mg.

The suspension must be mixed until homogeneous before sampling to obtain an accurate bead amount.

Flexible Biomolecule Immobilization

Potential coupling targets include:

• Monoclonal antibodies;

• Polyclonal antibodies;

• Antigens;

• Recombinant proteins;

• Natural proteins;

• Peptides;

• Enzymes;

• Streptavidin;

• Thiol-modified biomolecules;

• Other affinity ligands.

Magnetic Solid-Phase Processing

After coupling, MNH2UM-10 can be evaluated as a magnetic solid phase for:

1. Target capture;

2. Magnetic collection;

3. Removal of unbound sample components;

4. Washing;

5. Addition of detection reagents;

6. Signal measurement.

Suitable for Research-to-Production Projects

The product can support:

• Early feasibility testing;

• Antibody-coupling development;

• Assay formulation;

• Instrument compatibility testing;

• Pilot-scale production;

• Stability studies;

• Lot-consistency evaluation;

• Routine batch manufacturing.

Why Choose 2µm Magnetic Beads for Immunoassays?

Particle size is an important development parameter because it can influence bead number, available surface area, suspension behavior, reaction kinetics, magnetic collection and washing efficiency.

Balance Between Surface Area and Magnetic Collection

Smaller magnetic particles may provide more theoretical surface area per unit mass but can require stronger magnetic gradients or longer collection times.

Larger particles may be collected more easily but generally provide fewer individual particles per unit mass.

A 2µm format can therefore be evaluated as a middle option for assays requiring both biomolecule immobilization and practical magnetic handling.

A direct commercial comparison is available from BeaverBio, which offers a 2µm amino magnetic bead product for protein, antibody, peptide and oligonucleotide immobilization. Thermo Scientific also supplies amine-functional beads in the broader 1–4µm range at approximately50mg/mL.

Suitable for Repeated Magnetic Washing

Many magnetic immunoassays require several collection and washing steps.

The development team should evaluate:

• Time required for complete bead collection;

• Residual beads after aspiration;

• Pellet position;

• Redispersion after each wash;

• Signal loss during repeated washing;

• Background generated by incomplete washing.

Potential Compatibility With Automated Analyzers

MNH2UM-10 may be evaluated in automated magnetic immunoassay systems.

Compatibility depends on the specific analyzer, including:

• Magnetic module design;

• Reaction-cup geometry;

• Mixing method;

• Aspiration height;

• Washing sequence;

• Residual liquid volume;

• Detection timing.

The bead concentration and washing procedure should be validated on the intended instrument rather than transferred directly from a manual tube-based method.

Amino Surface Chemistry and Biomolecule Coupling

The amino surface of MNH2UM-10 can support different covalent immobilization strategies.

Amino magnetic beads should not be treated as universally ready for direct coupling to every biomolecule. In most protein and antibody workflows, a compatible bifunctional crosslinker or activated ligand is required.

BS3 or Other Amine-Reactive Crosslinkers

BS3 is a water-soluble homobifunctional NHS-ester crosslinker that can react with primary amino groups.

Thermo Scientific provides a reference procedure in which amine-functional magnetic beads are washed in a non-amine buffer, mixed with a protein or peptide and reacted with BS3. Its published example uses phosphate buffer, gentle mixing and subsequent magnetic washing. This procedure is a useful development reference but should not be treated as a validated protocol for MNH2UM-10 without optimization.

Important variables include:

• Crosslinker concentration;

• Protein concentration;

• Reaction pH;

• Reaction time;

• Bead concentration;

• Mixing efficiency;

• Quenching conditions.

Because both the bead surface and protein may contain multiple amino groups, this route generally produces random ligand orientation.

Sulfo-SMCC Amine-to-Sulfhydryl Coupling

Sulfo-SMCC is a heterobifunctional crosslinker containing an NHS ester and a maleimide group.

The NHS-ester end reacts with primary amino groups, while the maleimide end reacts with sulfhydryl-containing molecules. This route can be evaluated for thiolated antibodies, proteins, peptides or oligonucleotides when more selective functional-group targeting is required.

This strategy may be useful when:

• The ligand naturally contains accessible sulfhydryl groups;

• The ligand has been selectively thiolated;

• A defined spacer is required;

• Random amine-to-amine crosslinking is undesirable.

Buffers containing competing primary amines or sulfhydryls can interfere with this reaction and should be avoided during the applicable coupling step.

Reductive Amination of Aldehyde-Containing Ligands

Aldehyde-containing carbohydrates, glycoproteins or modified ligands can potentially react with surface amino groups through reductive amination under suitable conditions.

Thermo Fisher positions its amine-functional Dynabeads for covalent binding of carbohydrates, glycoproteins and glycolipids through this mechanism.

The reductant, buffer, pH, reaction time and ligand stability must be evaluated for the specific application.

Selecting the Appropriate Coupling Route

The coupling chemistry should be selected according to the ligand and assay requirements.

The final selection should be based on functional assay performance, not coupling yield alone.

Applications in Immunoassay Reagent Development

Magnetic Sandwich Immunoassays

A capture antibody can be immobilized on MNH2UM-10.

During the assay:

1. The antibody-coupled beads are incubated with the sample;

2. The target antigen binds to the capture antibody;

3. A labelled detection antibody binds to the captured target;

4. The bead complex is magnetically collected and washed;

5. The resulting signal is measured.

Important optimization parameters include bead dosage, antibody density, incubation time, washing efficiency and detection-antibody concentration.

Chemiluminescence Immunoassay

MNH2UM-10 can be evaluated as a magnetic solid-phase carrier in chemiluminescence immunoassay development.

Developers should confirm compatibility with:

• Capture antibody;

• Enzyme-labelled detection reagent;

• Blocking buffer;

• Wash buffer;

• Chemiluminescent substrate;

• Reaction vessel;

• Automated analyzer.

The bead itself should also be evaluated for background signal, sedimentation behavior and compatibility with repeated magnetic washing.

Electrochemiluminescence Immunoassay

MNH2UM-10 may be evaluated in electrochemiluminescence immunoassay research when a magnetic capture phase is required.

The development team should validate:

• Magnetic collection near the electrode or reaction zone;

• Compatibility with the electrochemiluminescent label;

• Background generated by bead or buffer components;

• Bead concentration;

• Electrode interaction;

• Washing and read sequence.

Suitability for a particular electrochemiluminescence platform cannot be determined by particle size alone.

Competitive Immunoassays

Antigens, antibodies, haptens or small-molecule conjugates may be immobilized on the amino magnetic beads for competitive assay development.

Potential applications include targets that are too small to support a conventional two-site sandwich format.

Antibody Detection

Antigens immobilized on MNH2UM-10 can be evaluated for capturing specific antibodies from research samples.

Immunomagnetic Separation

Ligand-coupled beads can be used to enrich a target before downstream analysis.

Potential targets include:

• Proteins;

• Cells;

• Microorganisms;

• Extracellular particles;

• Other affinity-recognized biological materials.

Immunoprecipitation and Affinity Capture

Antibody- or protein-coupled beads may also be evaluated for immunoprecipitation and affinity-purification research.

Thermo Scientific describes amine-functional magnetic particles as suitable for covalent coupling and magnetic isolation of antibodies, antigens, enzymes, proteins, nucleic acids and cells.

Recommended Antibody and Protein Coupling Workflow

The following workflow is a general development framework. It is not a validated product-specific protocol.

Step 1: Characterize the Ligand

Record the following information before beginning:

• Ligand type;

• Molecular weight;

• Protein concentration;

• Purity;

• Original buffer;

• Stabilizing additives;

• Available amino groups;

• Available sulfhydryl groups;

• Biological activity;

• Storage conditions.

Proteins supplied in buffers containing Tris, glycine, ethanolamine or other reactive components may require buffer exchange before coupling.

Step 2: Select the Coupling Chemistry

Choose the reaction according to the ligand:

• Amine-reactive crosslinker for suitable protein immobilization;

• Sulfo-SMCC for amine-to-sulfhydryl coupling;

• Reductive amination for compatible aldehyde-containing ligands;

• Another heterobifunctional crosslinker for specialized applications.

Step 3: Resuspend MNH2UM-10

Mix the original suspension until it is homogeneous before removing an aliquot.

Potential mixing methods include:

• Gentle inversion;

• Controlled vortexing;

• End-over-end rotation;

• Roller mixing;

• Validated low-energy sonication.

Avoid introducing excessive foam.

Step 4: Calculate the Required Bead Mass

MNH2UM-10 contains approximately50mg of beads per milliliter.

Use the following relationship:

Bead mass = suspension volume × 50mg/mL

Maintain the suspension in a homogeneous state during dispensing, especially when preparing multiple reaction batches.

Step 5: Wash and Exchange the Buffer

Collect the beads with a compatible magnetic separator.

Remove the original suspension medium and wash the beads with a buffer suitable for the selected crosslinker.

For NHS-ester reactions, non-amine buffers are generally preferred because primary amine-containing buffers can consume the reactive reagent. Thermo Scientific lists phosphate, HEPES, bicarbonate/carbonate and borate systems as examples in its amine-bead protocol.

Do not allow the beads to dry during washing.

Step 6: Activate the Beads

Add the selected crosslinker under controlled conditions.

Evaluate:

• Crosslinker-to-bead ratio;

• Activation pH;

• Bead concentration;

• Reaction temperature;

• Activation time;

• Mixing rate.

Step 7: Add the Antibody or Protein

Test multiple ligand-to-bead ratios rather than relying on one condition.

Excessive ligand input may increase cost or create steric crowding without improving analytical performance.

Step 8: Maintain Continuous Mixing

Keep the beads suspended during activation and coupling.

Uneven mixing can produce inconsistent surface exposure and batch variability.

Step 9: Quench or Block Residual Reactive Groups

After coupling, introduce an appropriate quenching or blocking reagent.

The blocking formulation should reduce non-specific interactions without interfering with target binding or signal generation.

Step 10: Wash the Coupled Beads

Remove:

• Unbound ligand;

• Residual crosslinker;

• Reaction by-products;

• Excess blocking reagent.

Use a consistent magnet, collection time and aspiration method.

Step 11: Resuspend in Storage Buffer

Potential formulation variables include:

• Buffer type;

• pH;

• Ionic strength;

• Protein stabilizer;

• Synthetic stabilizer;

• Surfactant;

• Preservative;

• Sugar or polyol;

• Final bead concentration.

The storage buffer should be optimized for both particle stability and ligand activity.

Step 12: Evaluate Coupling Efficiency

One practical approach is to compare the ligand concentration before coupling with the concentration remaining in the supernatant after coupling.

A simplified calculation is:

Coupling efficiency (%) =
[(initial ligand − ligand remaining in supernatant) ÷ initial ligand] × 100

Thermo Fisher lists absorbance measurement, fluorescent labelling and radioactive labelling as possible approaches for estimating ligand uptake.

Coupling efficiency should be interpreted together with functional binding activity.

How to Optimize MNH2UM-10 in an Immunoassay

Optimize Bead Dosage

Evaluate several bead concentrations in the final assay.

Too few beads may limit target capture. Excessive bead concentration may increase reagent usage, washing requirements or non-specific signal.

Optimize Ligand Density

Prepare conjugates with different ligand-loading levels.

Compare:

• Coupling efficiency;

• Target-binding capacity;

• Background signal;

• Signal-to-noise ratio;

• Detection sensitivity;

• Reagent stability.

The conjugate with the highest protein loading is not necessarily the best-performing assay reagent.

Optimize Blocking Conditions

Potential blockers may include:

• Protein-based blockers;

• Casein-derived formulations;

• Gelatin;

• Synthetic polymers;

• Nonionic surfactants;

• Salts;

• Combined blocking systems.

Blocking performance should be evaluated using negative samples and relevant biological matrices.

Optimize Magnetic Separation

Confirm:

• Collection time;

• Magnet strength;

• Vessel geometry;

• Sample volume;

• Pellet position;

• Residual liquid;

• Bead loss after aspiration;

• Redispersion after washing.

If magnetic collection is incomplete, possible causes include high solution viscosity, particle aggregation, an unsuitable magnet or insufficient separation time. Thermo Fisher includes viscosity and protein-mediated aggregation among its troubleshooting considerations for magnetic bead collection.

Optimize Incubation Time

Evaluate both sample-incubation and detection-incubation periods.

Longer incubation does not always improve performance and may increase non-specific interactions.

Evaluate Sample-Matrix Effects

Depending on the intended assay, interference studies may include:

• Hemoglobin;

• Bilirubin;

• Lipids;

• Rheumatoid factor;

• Heterophilic antibodies;

• Biotin;

• Anticoagulants;

• High concentrations of non-target proteins;

• Sample preservatives.

Evaluate Stability

Stability studies should cover:

• Uncoupled bead raw material;

• Activated intermediate;

• Ligand-coupled beads;

• Complete finished reagent.

Recommended studies include accelerated stability, real-time stability, transport simulation and in-use stability.

Quality Control for Research and Batch Production

MNH2UM-10 should be evaluated using both physicochemical testing and application-specific functional testing.

Appearance and Dispersion

Inspect:

• Suspension appearance;

• Visible aggregates;

• Sedimentation behavior;

• Redispersion;

• Homogeneity after mixing.

Particle Size

Confirm the nominal particle size and monitor particle-size distribution using an appropriate validated method.

Solids Content

Verify the solids concentration because it affects:

• Bead-mass calculations;

• Ligand consumption;

• Coupling yield;

• Final assay dosage;

• Manufacturing output.

Amino Surface Reactivity

A model ligand or standardized crosslinking reaction can be used to evaluate the functional reactivity of the bead surface.

Magnetic Collection Performance

Use standardized conditions, including:

• Magnet type;

• Sample volume;

• Bead concentration;

• Container;

• Buffer;

• Collection time.

Coupling Performance

Perform a standardized coupling reaction with a representative antibody or protein.

Potential measurements include:

• Protein depletion from the supernatant;

• Colorimetric protein analysis;

• Fluorescent ligand analysis;

• Functional target-binding assay;

• Immunoassay signal.

Non-Specific Binding

Compare:

• Unmodified beads;

• Activated beads;

• Blocked beads;

• Ligand-coupled beads;

• Negative sample matrices.

Functional Assay Performance

Recommended evaluation items include:

• Blank signal;

• Negative-sample signal;

• Positive-sample signal;

• Signal-to-background ratio;

• Analytical sensitivity;

• Precision;

• Recovery;

• Linearity;

• Specificity;

• Hook effect;

• Stability.

Lot-to-Lot Consistency

For routine production, establish acceptance ranges for critical raw-material and assay-performance parameters.

Final lot approval should be based on the performance of the complete immunoassay system rather than particle characterization alone.

Scale-Up and Bulk Supply for Immunoassay Manufacturers

MNH2UM-10 can support projects progressing from research evaluation to batch manufacturing.

Evaluation Stage

Evaluation samples can be used to screen:

• Coupling route;

• Crosslinker concentration;

• Ligand-to-bead ratio;

• Blocking formulation;

• Magnetic separation;

• Assay sensitivity;

• Background signal.

Pilot-Scale Stage

Pilot quantities can support:

• Process confirmation;

• Coupling scale-up;

• Reagent formulation;

• Automated-analyzer validation;

• Stability studies;

• Initial batch-consistency assessment.

Batch-Production Stage

Bulk supply planning may include:

• Annual demand;

• Forecasted order schedule;

• Packaging volume;

• Quality specifications;

• Technical documentation;

• Reserved-lot requirements;

• Change-control requirements;

• Safety-stock planning.

Important Scale-Up Parameters

A laboratory coupling process should not be enlarged only by multiplying every reagent volume.

The following factors should also be revalidated:

• Reaction-vessel geometry;

• Mixing efficiency;

• Mass transfer;

• Reagent-addition order;

• Temperature uniformity;

• pH control;

• Magnetic collection;

• Washing efficiency;

• Hold time;

• Final resuspension.

Custom Amino Magnetic Bead Services

Customized requirements can be discussed according to the intended immunoassay and production volume.

Potential customization options include:

• Alternative particle sizes;

• Customized solids content;

• Adjusted amino-group density;

• Customized suspension buffer;

• Alternative preservative systems;

• Customer-specified pH;

• Special packaging volumes;

• Pilot-scale manufacturing;

• Bulk manufacturing;

• OEM packaging;

• Private-label service;

• Customer-specific quality testing.

Customization feasibility depends on the requested specification, application, validation requirements and order quantity.

Storage and Handling Recommendations

Store MNH2UM-10 according to the product label, technical data sheet and lot-specific certificate of analysis.

General handling recommendations include:

• Mix thoroughly before sampling;

• Keep the suspension homogeneous during dispensing;

• Use clean and calibrated pipetting equipment;

• Avoid bead drying during magnetic washing;

• Prevent microbial and chemical contamination;

• Confirm buffer compatibility before buffer exchange;

• Avoid unvalidated freezing;

• Avoid unnecessary exposure to extreme temperatures;

• Record the product lot number;

• Evaluate finished-conjugate stability separately.

Commercial amine-bead protocols often warn that drying or freezing can cause aggregation, but the applicable conditions for MNH2UM-10 should follow its own technical documentation.

Frequently Asked Questions

What is MNH2UM-10?

MNH2UM-10 is a 2µm amino-functional magnetic bead suspension supplied at 5% w/v solids for biomolecule coupling, immunoassay development, process scale-up and batch production.

What is the concentration of MNH2UM-10?

The product is supplied at 5% w/v, equivalent to 50mg/mL.

What functional group is present on the bead surface?

The particle surface contains primary amino groups, commonly written as NH₂ groups.

What biomolecules can be coupled to MNH2UM-10?

Potential coupling targets include antibodies, antigens, proteins, peptides, enzymes, streptavidin and suitably modified oligonucleotides.

Can an antibody be coupled directly to the beads?

A suitable crosslinker or activation system is normally required. The appropriate chemistry depends on the antibody’s available functional groups and the desired conjugate structure.

Which coupling methods can be evaluated?

Potential routes include BS3 or other amine-reactive crosslinkers, Sulfo-SMCC amine-to-thiol coupling and reductive amination of suitable aldehyde-containing ligands.

Why choose a 2µm particle size?

The 2µm particle format can provide a practical balance between particle surface, suspension behavior and magnetic handling for immunoassay development.

Can MNH2UM-10 be used for chemiluminescence immunoassays?

MNH2UM-10 can be evaluated as a magnetic solid-phase carrier in chemiluminescence immunoassay development. Compatibility with the complete reagent and instrument system must be validated.

Can it be used for electrochemiluminescence immunoassays?

The beads may be evaluated in electrochemiluminescence immunoassay research. Compatibility with the electrode, magnetic module, detection label and assay formulation should be confirmed experimentally.

Does 5% solids mean the product is ready to use without dilution?

No. The 5% suspension is a concentrated raw material. The optimal working concentration should be determined during coupling and assay development.

Does higher antibody loading always improve sensitivity?

No. Excessive ligand density may cause steric hindrance, reduced accessibility or increased non-specific binding. Multiple ligand-to-bead ratios should be compared.

How can coupling efficiency be measured?

One approach is to compare the protein concentration before coupling with the concentration remaining in the supernatant after coupling. Functional binding activity should also be measured.

How should the suspension be mixed before use?

Mix the product until homogeneous using a validated method such as controlled inversion, vortexing, roller mixing or gentle sonication.

Can MNH2UM-10 be used with automated immunoassay analyzers?

It can be evaluated for automated systems. Magnetic collection, aspiration, washing, mixing and redispersion must be validated on the specific analyzer.

What should be done if the beads do not collect completely?

Check magnet strength, collection time, bead concentration, solution viscosity, particle aggregation and vessel geometry.

Is MNH2UM-10 a finished diagnostic reagent?

No. MNH2UM-10 is supplied as a magnetic bead raw material for research and reagent development. The customer is responsible for validating the finished reagent and its intended application.

Are evaluation samples available?

Evaluation samples can be discussed according to the intended application, target ligand and required test quantity.

Is bulk supply available?

Pilot-scale and bulk supply can be arranged for qualified research, development and manufacturing projects.

Can the concentration or packaging be customized?

Customized solids content, suspension buffer, particle specifications and packaging formats may be evaluated according to project requirements.

Request a Sample or Bulk Quotation

Contact SHBC to request evaluation samples, technical information or bulk pricing for MNH2UM-10 2µm Amino Magnetic Beads.

Please provide the following project information:

• Intended immunoassay application;

• Target antibody, antigen or protein;

• Preferred coupling method;

• Required evaluation quantity;

• Estimated pilot quantity;

• Expected annual demand;

• Preferred packaging volume;

• Required technical documents;

• Required quality documents;

• Target development schedule;

• Custom specification requirements.

SHBC supports amino magnetic bead projects from early coupling evaluation and immunoassay optimization to pilot production and bulk manufacturing.