NEW: ProActive® Microspheres

Our new line of protein activated microspheres, developed in response to numerous customer requests, continues our tradition of supplying only the best microspheres available in the world.

• ProActive Streptavidin coated superparamagnetic beads, the core of our new product line, serve as a generic magnetically responsive solid phase, to which a variety of biotinylated items can be attached.
• ProActive Protein A coated magnetic microspheres provide an IgG-binding affinity support that is extremely easy to manipulate.
• ProActive GAM magnetic microspheres: goat anti-mouse Fc-specific IgG binds mouse IgG's and orients them correctly for high activity with lessprimary Ab.

Streptavidin, protein A, and GAM coated non-magnetic, polymeric microspheres are also available in several sizes. Some of the more common applications of protein-coated microspheres include:

• Affinity Chromatography
• Multi-purpose Solid Phase for Immunoassays
• Nucleic Acid Hybridization
• Immunoselective Cell Separation
• DNA Sequencing

All of our coating work (for standard products and custom orders) is backed up by our years of experience in the microsphere business. See the Protein Coated Microspheres section of the printed list for a complete listing of currently available products. OR ask us to send you the latest list. As always...if the material that you need is not on the list, ask us to make it for you!

Uniform Microspheres,
Latex Particles, Beads or whatever you call them

• We have >2000 microspheres made of polystyrene (PS), other polymers, copolymers, terpolymers, and silica, too.
• They come in a variety of densities: 0.9 - 2.3 g/ml.
• All Sizes (nano- to millimeters) Our microspheres are available in diameters from ~0.020µm (20nm) to 1000µm (1mm).
• Size uniformity is excellent: c.v.'s are typically <3% (often~1%).
• in a Rainbow of Colors... We offer >300 different dyed microspheres in colors from red to beyond violet, as well as black, white, and gray. Bright primary colors for easy color identification and mixing of colors; others are very dark, like ink, for good contrast. Ask for help with color selection. We can make other size/color combinations, according to your need. We're ready to dye for you!
• with Fluorescent dyes, too... We have >30 different sized microspheres colored with >10 different dyes of various excitation and emission wavelengths. Ask for our separate technical note on fluorescent dyed microspheres, which contains excitation and emission spectra, so you can choose the ones you need. We will try to make any size and color you need.
• and Different Flavors! Surface chemistries range from hydrophobic (plain polystyrene) to very hydrophilic surfaces imparted by a wide variety of functional surface groups:
  • aldehyde -CHO
  • aliphatic amine -CH₂-NH₂
  • amide -CONH₂
  • aromatic amine-Ø-NH₂
  • carboxylic acid -COOH (3 dif. types)
  • chloromethyl -CH₂-Cl
  • epoxy
  • hydrazide -CONH-NH₂
  • hydroxyl -OH
  • sulfate -SO₄
  • sulfonate -SO₃
    

estapor- SuperParaMagnetic Microspheres

• Original recipe: Various types of ~1 µm diameter COOH- or -NH₂ modified microspheres contain 12, 20, 40, or 60% magnetite. Truly superparamagnetic, they respond to a magnet but display no residual magnetism. These microspheres can be used for direct adsorption of proteins, or surface groups can be used for covalent coupling of ligands (proteins, DNA, etc.)
• The narrow size distribution type were designed for better performance in cell depletion applications. These newer magnetic microspheres and the encapsulated ones (next paragraph) were developed in response to customer requests.
• Encapsulated microspheres (magnetite-rich core + PS shell), with COOH and NH₂surface groups make better solid supports for applications using enzymes- there is no iron on the surface!

Uniform Silica Microspheres

Our non-porous inorganic beads are useful in molecular biology and immunoassays.

• Diameters 0.3 - 5 µm, c.v. < 10%, density 1.96 g/ml
• High temperature stability (to 1000°C).
• Natural hydroxide surface (low protein adsorption) or a wide variety of other surface groups for covalent coupling. Using silane coupling agents, we can put almost any functional group on the silica microsphere surface.

Custom Synthesis- Ask us!

If you can imagine it and need it and we don't have it, then we'll try to make it for you. That is how we got > 2000 different products. We stock and make polymeric microspheres and beads of all kinds (sizes, surface chemistries, colors, and protein coatings). Give us a test!