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Caption: Researchers have developed a new cell sampling method using tiny nanostraws.

Tiny nanostraws may offer a glimpse into a cell’s contents without causing any damage to the cell.

The nanostraws were developed by researchers at Stanford University, who devised a method of sampling cell contents without disrupting its natural processes, which is a staple of current cell sampling methods.

The new method relies on tiny tubes 600 times smaller than a stand of hair that allow researchers to sample a single cell at a time. The nanostraws are able to penetrate a cell’s outer membrane without damaging it and draw out proteins and genetic material from the cell’s salty interior.

“It's like a blood draw for the cell,” Nicholas Melosh, an associate professor of materials science and engineering and senior author on a paper, said in a statement.

According to Melosh, this technique will significantly impact the understanding of cell development and could yield much safer and effective medical therapies because it allows for long term, non-destructive monitoring.

“What we hope to do, using this technology, is to watch as these cells change over time and be able to infer how different environmental conditions and 'chemical cocktails' influence their development—to help optimize the therapy process,” he said.

If researchers gain a better grasp on how a cell works they can address those processes directly.

“For stem cells, we know that they can turn into many other cell types but we do not know the evolution—how do they go from stem cells to, say, cardiac cells?” Yuhong Cao, a graduate student and first author on the paper, said in a statement. “This sampling technique will give us a clearer idea of how it's done.”

A benefit of the sampling method is it could inform cancer treatments and answer questions about why some cancer cells are resistant to chemotherapy while others are not.

“With chemotherapy, there are always cells that are resistant,” Cao said. “If we can follow the intercellular mechanism of the surviving cells, we can know, genetically, its response to the drug.”

The nanostraws are grown in a small sampling platform designed to mimic biology called the Nanostraw Extraction (NEX) sampling system.

Cells divide and change over time, with thousands of chemical reactions occurring within each cell every day, which makes it difficult to truly understand the inner workings of cells.

Currently, scientists use a method of cell sampling called lysing, which ruptures the cell. However, once a cell is destroyed it cannot be sampled from again.

Cells in our bodies are connected by a system of ‘gates’ through which they send each other nutrients and molecules.

Melosh was inspired to develop the new system when he observed the intercellular gates after he was trying to determine a non-destructive way of delivering substances, including DNA or medicines, inside cells.

The new sampling system is the reverse of that process, as scientists are able to observe what’s happening within a cell.

When the research team compared their cells samples from the NEX with cell samples taken by breaking the cells open, they found that 95 percent of the samples were congruous.

The team also found that when they sampled from a group of cells day after day, certain molecules that should be present at constant levels remained the same, which indicated that their sampling accurately reflected the cell’s interior.

The team not only sampled generic cell lines but also with human heart tissue and brain cells grown from stem cells and in each case the nanostraw sampling reflected the same cellular contents as lysing the cells.

The study was published in the Proceedings of the National Academy of Sciences of the United States of America.

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