Fluorescent labeling of cells and biomolecules with nanocrystal quantum dots

Fluorescent nanoparticles, such as nanocrystal quantum dots (QDs), novel nanometer-size probes and have the potential to be used as easy imaging tool for molecular biology and bioimaging including medical applications, since some nanocrystals emit higher and far longer fluorescence than conventional organic probes. QDs are now becoming widely used in biotechnology and medical applications. QDs have several advantages over organic fluorophores with regard to high luminescence, stability against photobleaching, and a range of fluorescence wavelengths from blue to infrared depending on the particle size. In this review, we reported labeling of some kinds of immune cells and biomolecules with several QDs coated with hydrophilic carboxyl/amine groups, and reported that we could image the circulation of mouse lymphocytes in vivo by QDs. In addition, we also reported here about the cytotoxicity of these nanocrystals.