New technique allows nanobiopsies of living cells

Researchers at UC Santa Cruz have developed a robotic "nanobiopsy" system that can extract tiny samples from inside a living cell without killing it.

The single-cell nanobiopsy technique is a powerful tool for scientists working to understand the dynamic processes that occur within living cells, according to Nader Pourmand, professor of biomolecular engineering in UCSC's Baskin School of Engineering.

"We can take a biopsy from a living cell and go back to the same cell multiple times over a couple of days without killing it. With other technologies, you have to sacrifice a cell to analyze it," said Pourmand, who leads the Biosensors and Bioelectrical Technology group at UCSC.

The nanobiopsy platform is the latest device his group has developed that uses nanopipettes, which are small glass tubes that taper to a fine tip with a diameter of just 50 to 100 nanometers. "We can create nanopipettes in the lab—it doesn't require an expensive nanofabrication facility," Pourmand said.

In a study published in ACS Nano, Pourmand's group used the system to extract from living cells tiny amounts of cellular material estimated to be about 50 femtoliters (a femtoliter is one quadrillionth of a liter). That's about one percent of the volume of a human cell. The researchers were able to extract and sequence RNA from individual human cancer cells. They also extracted mitochondria (tiny subcellular organelles) from human fibroblasts and sequenced the mitochondrial DNA.