Spherotech

As a global supplier of microparticle solutions, our experienced scientists manufacture high quality latex, fluorescent, paramagnetic, ferromagnetic and colored dyed microparticles. Our microsphere portfolio offers you:
• Particle size dispersion specific to your requirements.
• Functionalized surface chemistry
• Coated microbeads with antibodies, proteins, or ligands
• Cross-linked particles for greater organic solvent stability
• Flow cytometry grade microbeads for alignment, calibration, compensation, counting and sorting
Microparticles manufactured by Spherotech are utilized for:
• Fluorescence immunoassay
• Enzyme immunoassay (EIA)
• Fluorescence microscopy
• Confocal fluorescence microscopy
• Flow cytometry/ image cytometry
• Magnetic cell separation
• Magnetic particles EIA
• Microfluidics
• Other research and industrial applications

The SPHEROTM polystyrene particles are prepared by conventional emulsion polymerization with styrene as the monomer and potassium persulfate or benzoyl peroxide as polymerization initiator. In general, microparticles less than 0.5μm are prepared in one step. Larger particles are prepared by step wise growing of smaller particles with the addition of styrene monomer and initiator without any additional detergent. The microparticles are cleaned by repeated centrifugation. Cleaned microparticles are resuspended in deionized water. Sodium azide (0.02%) is added as a bacteriostatic. As a result, the SPHEROTM microparticles can be coated with proteins without further cleaning.

Microparticles made using potassium persulfate as the initiator have sulfate groups on their surface. As a result, these particles are negatively charged and are hydrophilic, as shown in equation (1). PDF Potassium Persulfate

The SPHEROTM polystyrene particles greater than 3μm are usually prepared using benzoyl peroxide as the initiator. These particles are relatively more hydrophobic, as shown in equation (2). PDF BPO

SPHEROTM polystyrene particles are composed of linear polystyrene without any cross-linking agent. These particles cannot tolerate organic solvents such as toluene, xylene, chloroform, methylene chloride, acetonitrile, dimethyl formamide or acetone. However, SPHEROTM polystyrene particles are stable in the presence of some water miscible solvents such as dimethyl sulfoxide and alcohols. Uniform size cross-linked polystyrene particles that are stable in the presence of organic solvents are also available. Uniform SPHEROTM polystyrene particles are ideal for use in immunoassays such as latex agglutination, particle based enzyme immunoassays and fluorescence immunoassays. A tight size range of SPHEROTM polystyrene particles is maintained by monitoring size using a NICOMP Laser Particle Sizer (for particles less than 3μm) and a Scanning Electron Microscope and/ or Beckman Coulter MultisizerTM 3 for larger particles. Although the size measurements are accurate, these particles are not certified for use as a calibration standard for size measurements or pore size analysis.
These polystyrene beads are used during the production of our other product lines including fluorescent, functionalized, crosslinked, magnetic, and protein coated particles. In addition, Spherotech polystyrene beads are used to manufacture a wide range of flow cytometry beads for applications, such as calibration, alignment, sensitivity measurements, compensation, and various kits for assay development.

AccuCount Particles
Coated Ferromagnetic Particles
Coated Fluorescent Particles
Coated Magnetic Particles
Coated Particles
Color Particles
COMPtrol Antibody Capture Beads
Drop Delay Calibration Particles
Easy Calibration Fluorescent Particles
EasyComp Fluorescent Particles
Ferromagnetic Particles
Flow Cytometry Multiplex Bead Assay Particles
Flow Cytometry Particle Size Standard Kit
Fluorescent Magnetic Particles
Fluorescent Particle Slides
Fluorescent Particles
Functionalized Polystyrene Beads
Gold Nanoparticles
IR Fluorescent Particles
Magnetic Blue Particle Array Kit
Magnetic Separators
Nano Fluorescent Size Standard Kit
Other Alignment Particles
Other Calibration Particles – Blank APC IR Linear
Paramagnetic Magnetic Particles
Polystyrene Particles
Rainbow Calibration Particles EuroFlow
Rainbow Calibration Particles
Rainbow Fluorescent Particles
Silica High Iron Nano Superparamagnetic Particles
Silica Particles
Superparamagnetic Particles
Supra Rainbow Midrange Fluorescent Particles
Ultra Rainbow Calibration Particle
Ultra Rainbow Fluorescent Particles
Ultra Rainbow Quantitative Particle Kit
BPO
Potassium Persulfate