Section 6.5 - FluoSpheres and TransFluoSpheres Fluorescent Microspheres

Although low molecular weight reactive dyes are versatile and easy to use, they are not without limitations (see Limitations of Low Molecular Weight Dyes). For example, the fluorescence output of the dye–biomolecule conjugate is often limited by the number of dyes that can be attached to the biomolecule without disrupting its function. Our highly fluorescent microspheres — both the FluoSpheres (Figure 6.40) and TransFluoSpheres (Figure 6.41) beads — provide a means of overcoming this limitation. Moreover, our TransFluoSpheres beads are designed to facilitate multicolor detection, particularly in applications that use lasers, with their inherent limited number of excitation wavelengths. TransFluoSpheres beads contain a series of two or more proprietary dyes that have been carefully chosen to ensure excited-state energy transfer between the dyes. This unique strategy enables fine-tuning of both the excitation and emission wavelengths of the microspheres so that they match a particular instrument’s excitation source and detection sensitivity and complement the spectra of other fluorophores in a multicolor experiment.