Fluorescent Carboxyl Ferromagnetic Particles, Nile Red, 1% w/v, 4.0-4.9 µm

Our fluorescent microparticles are prepared by either staining polystyrene particles with a fluorophore solution or by polymerizing a fluorophore in styrene in the presence of polystyrene core particles. As a result, a wide variety of fluorescent particles can be prepared ranging in size, type of fluorophore, fluorescence intensity and surface functional groups. The fluorophores chosen for use in the preparation of the fluorescent particles are water insoluble and therefore are very stable. These fluorophores, once incorporated into the particles, do not leach and their color and fluorescence remains stable for long periods of time under proper storage conditions. Unlike paramagnetic particles that are made using iron oxide, the Ferromagnetic Particles are prepared using chromium dioxide coated onto uniform polystyrene particles. These particles retain magnetism once exposed to a magnetic field. The particles can be demagnetized and re-magnetized repeatedly and reproducibly. Ferromagnetic particles have been used for studying mechanotransduction across the cell surface and through the cytoskeleton by binding ferromagnetic particles to cell surface receptors and applying mechanical stress directly to the receptor using a device to twist the magnetic particle on the cell surface.