Nanoscale tweezers can perform single-molecule biopsies on individual cells

Using electrical impulses, the 'tweezers' can extract single DNA,sproteins and organelles from living cells without destroying them.

A new technique, developed by a team led by Professor Joshua Edel and Dr Alex Ivanov at Imperial College London, enables researchers to extract single molecules from live cells, without destroying them. The research, published today in the journal Nature Nanotechnology, could help scientists in building up a 'human cell atlas', providing new insights into how healthy cells function and what goes wrong in diseased cells.

Professor Joshua Edel, from the Department of Chemistry at Imperial, said: "With our tweezers, we can extract the minimum number of molecules that we need from a cell in real time, without damaging it. We have demonstrated that we can manipulate and extract several different parts from different regions of the cell - including mitochondria from the cell body, RNA from different locations in the cytoplasm and even DNA from the nucleus."

The tweezers are formed from a sharp glass rod terminating with a pair of electrodes made from a carbon-based material much like graphite. The tip is less than 50 nanometers (a nanometre is one-millionth of a millimetre) in diameter and is split into two electrodes, with a 10 to 20-nanometre gap between them.

By applying an alternating current voltage, this small gap creates a powerful highly localised electrical field that can trap and extract the small contents of cells such as DNA and transcription factors - molecules that can change the activity of genes.