Red Fluorescent Polystyrene Microsphere Suspensions - Solids, 0.025 µm - 3.0 µm

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): Red fluorescent (580/605)
• 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.

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