Belling the Cat—Tagging Live Cells with Quantum Dots

Abstract

Featured article: Jaiswal JK, Mattoussi H, Mauro JM, Simon SM. Long-term multiple color imaging of live cells using quantum dot bioconjugates. Nat Biotechnol 2003;21:47–51.3 Fluorescence imaging allows high-resolution, noninvasive monitoring of live cells and organisms and their responses to the environment. Organic fluorophores have been the staple for most of these developments; however, some of the limitations of organic fluorophores have generated a need for other fluorescent probes for live and multicolor imaging. Quantum dots (QDs)4 are inorganic fluorophores that offer many improvements over the organic fluorophores. These nanoparticles, first synthesized in 1980s, were not tested for biological applications until the late 1990s [reviewed in (1)], and the limitations of QDs, such as poor long-term stability in aqueous solution, toxicity associated with their composition, and safe delivery of QDs into live cells, prevented the full realization of the live cell–imaging potential of QDs. In 1990, a few coatings were developed to stabilize QDs in water and conjugate them with biomolecules, such as avidin and antibodies, for targeted labeling. One such coating developed by our collaborators at the Naval Research Laboratory in …