Small is Beautiful

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Science  16 Jan 2004:
Vol. 303, Issue 5656, pp. 289
DOI: 10.1126/science.303.5656.289a

Although many biologists are interested in phenomena operating on micrometer-to-nanometer scales, they often rely on their physical science colleagues in adapting existing technology to new uses: for example, x-ray crystallography for structure determination of macromolecules and atomic force microscopy for probing single biomolecules. Alivisatos reviews the recent crossover of quantum dots—clusters of roughly a few thousand inorganic atoms with favorable properties for biological imaging (intense stable fluorescence in the visible region). Lidke et al. illustrate their use with epidermal growth factor—quantum dot (EGF-QD) conjugates. EGF binds to members of the erbB family of receptor tyrosine kinases, and inappropriate expression of these receptors is implicated in some types of cancer. Fortunately, EGF-QDs also bind to these receptors, making it feasible to monitor endocytosis and intracellular trafficking of the growth factor. Coupling the use of these ligands to expression of various fluorescent pairs of erbB receptors suggested that heterodimerization of erbB1 and B2 (but not erbB1 and B3) is triggered by the interaction with EGF. — GJC

NatureBiotechnol. 22, 47; 10.1038/nbt929 (2004).

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