Microspheres (also called latex beads or latex particles) are spherical particles in the colloidal size range that are formed from an amorphous polymer such as polystyrene. Our Molecular Probes™ TransFluoSpheres™ beads are manufactured using high-quality, ultraclean polystyrene and are loaded with two (or more) fluorescent dyes to produce a microspheres that can be excited by a commonly used excitation source (for example, the 633 nm spectral line of the Red He-Ne laser) but emit at much longer wavelengths, facilitating multicolor experiments and allowing the use of broadband excitation and emission filters. TransFluoSpheres™ microspheres typically show little or no photobleaching, even when excited with the intense illumination required for fluorescence microscopy.

TransFluoSpheres™ Microsphere Specifications:

• Label (Ex/Em): Red-fluorescent (633/720)
• Nominal bead diameter: 0.04 μm
• Coupling surface: Carboxylate
• Solids: 2%

Characteristics of the Carboxylate Coupling Surface
Carboxylate-modified FluoSpheres™ beads have a high density of pendent carboxylic acids on their surface, making them suitable for covalent coupling of proteins and other amine-containing biomolecules using water-soluble carbodiimide reagents such as EDAC.

Key Applications of Microspheres:
• Instrument calibration (flow cytometry, microscopy, HTS, HCS)
• Flow testing (microfluidics, blood flow, water flow, and air flow)
• Cell biology tracers (cell differentiation and cell tracing)
• Immunoassays (agglutination tests, ELISA, particle capture, and contrast reagents)

Choices for Fluorescent Microspheres
Among our complete offering of fluorescent microspheres products, you’ll find beads with these variations:
• Ten fluorescent colors
• Ten nominal bead diameters: 0.02 μm, 0.04 μm, 0.1 μm, 0.2 μm, 0.5 μm, 1.0 μm, 2.0 μm, 4.0 μm, 10.0 μm, and 15.0 μm
• Four surface modifications for protein coupling: carboxylate, sulfate, aldehyde-sulfate, amine
• Microspheres that are additionally precoupled with streptavidin, NeutrAvidin, biotin, europium, and platinum

Choices for Unstained Microspheres
We also offer hundreds of choices for UltraClean™ surfactant-free microspheres for research and commercial applications.

We’ll Make a Custom Microsphere Product for You
We will prepare custom orders upon request. Our custom conjugation service is efficient and confidential, and we stand by the quality of our work. We are ISO 13485:2000 certified.

For Research Use Only. Not intended for animal or human therapeutic or diagnostic use.