FluoSpheres™ Polystyrene Microspheres, 1.0 μm, yellow-green fluorescent (505/515), for tracer studies

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™ FluoSpheres™ beads are manufactured using high-quality, ultraclean polystyrene and are loaded with a variety of our proprietary dyes to create intensely fluorescent beads that typically show little or no photobleaching, even when excited with the intense illumination required for fluorescence microscopy.

For tracking particles and cells, tracing fluid dynamics, discriminating the size dependence of uptake or transport in vivo, etc., we offer more concentrated, 0.04 μm diameter FluoSpheres™ microspheres preparations (5% solids) that lack the sodium azide preservative present in the majority of our FluoSpheres™ products. The 0.04 μm particles are small enough to be microinjected or to be taken up by phagocytosis.

We also offer 1.0 μm FluoSpheres™ microsphere preparations that contain a much higher dye content than our other FluoSpheres™ products. This allows stronger signals to be generated using fewer microspheres per tracing experiment.

In many biological systems, the concentrated fluorescence and spherical shape of the FluoSpheres™ beads permit them to be detected against a relatively high but diffuse background fluorescence. Typically for these types of studies, the microspheres and the fluorescent dyes they contain are first extracted from the tissue sample, and then the fluorescence is quantified on a spectrofluorometer or fluorescence microplate reader. The use of fluorescent microspheres eliminates the radiation hazards and disposal hurdles associated with radiolabeled microspheres.

FluoSpheres™ Microsphere Specifications:

• Label (Ex/Em): Yellow-green fluorescent (505/515)
• Nominal bead diameter: 1.0 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.

Choices for FluoSpheres™ Fluorescent Microspheres
In addition to microspheres for tracing, investigate our complete offering of fluorescent microspheres products. Among those 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. For example, FluoSpheres™ beads can be prepared with intensities that are lower than those of our regular selection, a desirable feature in some multicolor applications. Our custom conjugation service is efficient and confidential, and we stand by quality of our work. We are ISO 13485:2000 certified.

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