Sci. STKE, Vol. 2005, Issue 290, pp. pl5, 28 June 2005
[DOI: 10.1126/stke.2902005pl5]
Quantum Dot-Based Cell Motility Assay
Weiwei Gu1, Teresa Pellegrino2, Wolfgang J. Parak2, Rosanne Boudreau1, Mark A. Le Gros3, Daniele Gerion2, A. Paul Alivisatos2, and Carolyn A. Larabell1,3*
1Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA.
2Department of Chemistry, University of California, Berkeley, CA 94720, USA.
3Physical Bioscience Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
Abstract: Because of their favorable physical and photochemical properties, colloidal CdSe/ZnS-semiconductor nanocrystals (commonly known as quantum dots) have enormous potential for use in biological imaging. In this report, we present an assay that uses quantum dots as markers to quantify cell motility. Cells that are seeded onto a homogeneous layer of quantum dots engulf and absorb the nanocrystals and, as a consequence, leave behind a fluorescence-free trail. By subsequently determining the ratio of cell area to fluorescence-free track area, we show that it is possible to differentiate between invasive and noninvasive cancer cells. Because this assay uses simple fluorescence detection, requires no significant data processing, and can be used in live-cell studies, it has the potential to be a powerful new tool for discriminating between invasive and noninvasive cancer cell lines or for studying cell signaling events involved in migration.
