Hopping Probe to Study Nanostructures at the Surface of Live Cells
Print-Friendly Version      Download Article as PDF

An international team of scientists, co-led by University of Kentucky physiologist Gregory Frolenkov, has developed a technique for imaging nanostructures on the surface of living cells. The team developed “hopping probe ion conductance microscopy,” in which a nanoscale probe “hops” over the surface of a cell. This hopping probe, similar to a sewing machine needle, never touches the surface of the cell, unlike previous “sliding” probes that can damage cells.

The technique, which was published in the journal Nature Methods in April, allows researchers to get high-resolution, three-dimensional images of the surface of complex living cells.

“Until now, we had no idea what the surface of most live cells looked like at nanoscale resolution,” says Frolenkov, who came to UK in 2005 from the NIH’s National Institute on Deafness and Other Communication Disorders.

Frolenkov and his research team are studying the mechanosensation—the conversion of mechanical stimuli into neuronal signals—in the inner ear and needed a tool to visualize nanoscale objects on the surface of live inner ear cells. “Many diseases affect the cell surface, and abnormal mechanosensitivity of the cell is involved in deafness, pain, cardiac arrhythmia, and even cancer.

“Now we can see nanostructures such as individual protein or protein complexes in a living cell and probe their function. We expect that our technique, together with emerging high-resolution imaging techniques looking inside the cell, will clarify the mechanisms of a number of diseases, just as optical microscopes revolutionized medicine centuries ago,” Frolenkov says.

Co-principal investigators on the project were Yuri Korchev of the Imperial College London Division of Medicine and David Klenerman of Cambridge University’s Department of Chemistry. Ruben Stepanyan of the UK Department of Physiology was also part of the research team.—JW

hopping probe image of ear hair

This image, taken with Gregory Frolenkov’s “hopping probe ion conductance microscopy” technique, shows stereocilia. These hair-like projections, with a diameter of only 100 to 250 nanometers, are lined up in several rows of increasing height. When the tiny filaments that connect the tips of these hairs stretch, they open ion channels and convert sound-induced vibrations into neuronal signals.

Enlarge Photo