18um Carboxyl Red-Fluo Microspheres CFR18UM-10 1%

18um Carboxyl Red-Fluo Microspheres CFR18UM-10

SHBC CFR18UM-10 are 18 μm carboxyl-functionalized red fluorescent microspheres developed for flow cytometry, fluorescence imaging, particle-based assays and biomolecule immobilization.

The microspheres feature 535 nm excitation, 610 nm emission and 1% solid content. Surface carboxyl groups support covalent coupling with antibodies, antigens, proteins and peptides.

Product Specifications

Batch-specific particle size, particle size distribution, fluorescence intensity and carboxyl content are available in the Certificate of Analysis.

Red Fluorescence at 535/610nm

CFR18UM-10 produces red fluorescence with excitation at approximately 535 nm and emission centered near 610 nm.

The optical profile is suitable for compatible flow cytometers, fluorescence microscopes, imaging systems and fluorescence readers.

Key Advantages

Uniform 18um Particle Size

Controlled particle sizing supports repeatable fluorescence detection, surface coupling and particle analysis.

Strong Signal per Particle

The large particle body provides a bright fluorescent signal for clear identification and imaging.

Reactive Carboxyl Surface

Surface COOH groups support covalent immobilization of antibodies, antigens, proteins, peptides and other amino-containing molecules.

Large Surface per Particle

The 18 μm diameter provides substantial surface area on each particle for ligand immobilization.

Easy Separation

The microspheres can be recovered by centrifugation during conjugation, washing and buffer exchange.

Custom and Bulk Supply

SHBC supports laboratory samples, customized specifications, pilot production and industrial batch supply.

Main Applications

Flow Cytometry

Suitable for particle detection, fluorescence channel evaluation, gating development and bead-based assay research.

Fluorescence Microscopy

The red fluorescent signal supports particle localization, distribution and imaging studies.

Particle-Based Immunoassays

Antibodies or antigens can be immobilized on the carboxyl surface for suspension immunoassays and agglutination research.

Biomolecule Immobilization

Suitable for coupling antibodies, proteins, enzymes, peptides and other amino-containing biomolecules.

Instrument Evaluation

Can be evaluated for fluorescence detection, particle counting, imaging and method development.

Fluid and Particle Tracing

Suitable for selected flow visualization, filtration, particle transport and distribution studies.

Microfluidic Research

Can be used for channel testing, large-particle transport, filtration and fluidic-device evaluation.

Cell–Particle Interaction Studies

May be evaluated in selected adhesion, cellular contact and phagocytic-cell studies.

Biomolecule Coupling

Surface carboxyl groups can be activated using EDC or EDC/NHS chemistry and reacted with primary amine groups on antibodies or proteins.

A general coupling workflow includes:

1. Wash and redisperse the microspheres.

2. Activate the surface carboxyl groups.

3. Add the antibody or target protein.

4. Block remaining reactive sites.

5. Wash and resuspend the conjugated particles.

6. Evaluate coupling efficiency and fluorescence performance.

Activation pH, protein concentration, reagent ratio and reaction time should be optimized for each biomolecule.

Coupling Benefits

CFR18UM-10 provides:

• Reactive surface carboxyl groups

• Large coupling surface per particle

• Stable covalent immobilization

• Easy centrifugation and washing

• Strong fluorescence detection

• Flexible ligand modification

• Compatibility with suspension assays

• Custom conjugation support

Flow Cytometry Considerations

Optimize the following parameters:

• Particle concentration

• Excitation source

• Emission filter

• Sample flow rate

• FSC and SSC settings

• Detector voltage

• Gating strategy

• Doublet discrimination

• Particle aggregation

Use an optical configuration compatible with excitation near 535 nm and emission near 610 nm.

Because the particles are 18 μm, confirm that the instrument flow cell, tubing and fluidics can process the particle size.

Imaging and Tracing Considerations

For microscopy and tracing studies, evaluate:

• Particle concentration

• Exposure time

• Objective magnification

• Excitation filter

• Emission filter

• Background fluorescence

• Particle settling

• Surface adsorption

• Image-analysis settings

Appropriate particle-free and fluorescence controls should be included.

Cell Study Considerations

The 18 μm particles are larger than many mammalian cells.

For cell-related research, evaluate:

• Cell type and diameter

• Particle-to-cell ratio

• Surface ligand density

• Incubation time

• Cell viability

• Particle adhesion

• Internalization capability

• Washing efficiency

The product may be more suitable for surface-contact studies or large phagocytic cells than for general cellular uptake.

Dispersion and Handling

Before use:

• Mix by gentle inversion or controlled vortexing

• Redisperse settled particles completely

• Avoid excessive bubbles and foam

• Protect the suspension from strong light

• Prevent the microspheres from drying

• Avoid repeated freeze-thaw cycles

• Confirm buffer compatibility

• Use clean laboratory equipment

Controlled bath sonication may be used to break weak aggregates. Avoid aggressive probe sonication.

Centrifugation and Washing

The 18 μm particles can generally be recovered by low-speed centrifugation.

Optimize centrifugation according to:

• Suspension volume

• Buffer viscosity

• Particle concentration

• Tube geometry

• Required recovery rate

Avoid excessive centrifugation that may form a compact pellet that is difficult to redisperse.

Application Limitations

CFR18UM-10 is generally unsuitable for conventional nitrocellulose membrane migration because of its large particle size.

Smaller submicron fluorescent microspheres are more appropriate for standard fluorescent lateral flow assays.

Instrument fluidics, cell compatibility and sedimentation should be evaluated before application.

Custom Carboxyl Fluorescent Microspheres

SHBC can customize fluorescent microspheres according to research and production requirements.

Customization options may include:

• Custom particle size

• Custom fluorescence wavelength

• Different fluorescence colors

• Carboxyl group density

• Solid content

• Dispersion buffer

• Surface modification

• Biomolecule conjugation

• Custom packaging

• OEM and ODM production

Please provide the target application, required wavelength, target biomolecule and order quantity when requesting customization.

Quality Control and Documents

Available product documents may include:

• Certificate of Analysis

• Technical Data Sheet

• Safety Data Sheet

• Particle size report

• Particle size distribution data

• Fluorescence spectrum

• Carboxyl content data

• Microscopy images

• Batch inspection report

Why Choose SHBC?

Shanghai SanYu Biotechnology Co., Ltd. supplies fluorescent microspheres, colored latex particles, magnetic beads and functional microsphere materials.

SHBC provides:

• Controlled microsphere manufacturing

• Stable particle size distribution

• Multiple fluorescence wavelengths

• Functional surface modification

• Batch-to-batch consistency

• Sample evaluation support

• Pilot and bulk production

• OEM and ODM services

Frequently Asked Questions

What is CFR18UM-10?

CFR18UM-10 is an 18 μm carboxyl-functionalized red fluorescent microsphere suspension with 1% solid content.

What are the excitation and emission wavelengths?

The excitation wavelength is 535 nm and the emission wavelength is 610 nm.

What is CFR18UM-10 mainly used for?

It is suitable for flow cytometry, fluorescence microscopy, particle-based assays, biomolecule coupling, instrument evaluation and tracing studies.

Can antibodies be coupled to CFR18UM-10?

Yes. Antibodies and proteins containing primary amine groups can be covalently coupled to the carboxyl surface.

Which coupling chemistry can be used?

EDC or EDC/NHS chemistry can be evaluated for activating surface carboxyl groups and coupling proteins.

Is CFR18UM-10 suitable for flow cytometry?

It may be used when the instrument fluidics can process 18 μm particles. Optical filters, scatter settings and gating conditions must be optimized.

Can CFR18UM-10 be used for cell uptake studies?

The particles are larger than many cells. They are more suitable for selected phagocytic-cell or cell-surface interaction studies.

Is CFR18UM-10 suitable for lateral flow assays?

No. The 18 μm particles are generally too large for conventional nitrocellulose membrane migration.

How should CFR18UM-10 be dispersed?

Use gentle inversion, controlled vortexing or compatible bath sonication while avoiding excessive foam and particle damage.

Can the particles be separated by centrifugation?

Yes. Centrifugation speed and time should be optimized according to the suspension volume, buffer and required recovery.

Can CFR18UM-10 be customized?

Yes. Particle size, fluorescence wavelength, carboxyl density, solid content, buffer, surface ligand and packaging can be customized.

Are samples and bulk quantities available?

Yes. SHBC supports laboratory samples, pilot orders and industrial batch production.

Request a Sample or Quotation

Contact SHBC for CFR18UM-10 samples, technical specifications, conjugation support and bulk pricing.

Please provide:

• Target application

• Target biomolecule

• Detection instrument

• Required quantity

• Preferred packaging

• Estimated annual demand

Product: 18um Carboxyl Red-Fluo Microspheres
Catalog Number: CFR18UM-10
Particle Size: 18 μm
Solid Content: 1%
Excitation/Emission: 535/610 nm
Surface Group: Carboxyl, COOH
Brand: SHBC
Manufacturer: Shanghai SanYu Biotechnology Co., Ltd.