Seeing cells without light: Brown chip tracks cell movement purely electrically
Engineers at Brown University observe migrating cells with a chip full of tiny electrodes instead of a microscope. No dyes, which can damage DNA, are needed.
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Video: YouTube · Brown University · youtube.com
Researchers at Brown University in the US have developed a method for tracking the movement of living cells without any optics at all. At its heart is a chip about half an inch square carrying around one million microscale electrodes. Instead of light, the sensor measures electrical capacitance: when a cell sits on an electrode, the signal changes. The result is an image made without lenses, a light source or a camera. The work was published in the journal Lab on a Chip.
Until now, cells often have to be labelled with fluorescent dyes for such observations. Such dyes "can cause DNA damage", explains co-first author Hyuntae Jeong. In tests, the team tracked individual human breast cancer cells and even captured cell division. Spherical cell clusters and honeycomb-like tissues of hundreds of thousands of cells could also be imaged – including so-called leader cells that guide migration at the edges.
The work was led by engineers Jacob Rosenstein and Ian Y. Wong. "The cells show up beautifully in the capacitance image and can be tracked automatically," Wong says. The project was funded by, among others, the US National Science Foundation and the National Institutes of Health.