Cellular uptake of fluorescent labelled biotin-streptavidin microspheres.

Amino functionalized, cross-linked, polystyrene microspheres were covalently loaded with streptavidin to which was coupled fluorescently labeled biotin and biotinylated-tagged DNA. These biotin-streptavidin microsphere conjugates were then successfully delivered into cells. The application of the streptavidin-biotin technology to these microspheres allows the effective delivery of any biotinylated material into intact mammalian cells, without the need for delicate procedures such as micro-injection.