Researchers at Imperial College London (ICL) have developed nanoscale tweezers, a new technology that allows them to extract single molecules from living cells without destroying them. It is expected that their research could allow them to build up a ‘human cell atlas’, providing insight into how healthy cells function and the malfunctions that take place in diseased cells.
The tweezers are made from a sharp glass rod terminating with a pair of electrodes made from a carbon-based material similar to graphite. Their tip measures at less than 50 nanometers (one millimeter is equal to a million nanometers) in diameter, and splits into two electrodes with a 10 to 20 nanometer gap between them. The application of alternating current voltage to the space between the two electrodes creates a localized electrical field that is able to trap and extract small contents of cells, such as DNA and transcription factors (molecules that can change the activity of genes).
The tweezers could allow for experiments which are not currently possible. Nerve cells, for example, require a lot of energy to fire signals around the body. Hence they contain mitochondria to help them function. By adding or removing mitochondria from single nerve cells, researchers could better understand the nervous system and neurodegenerative disease in particular.
Traditionally, such extractions involved bursting the cell. This would result in all of its contents getting mixed and the loss of spatial information as well as dynamic information such as molecular changes that took place in the cell over time.
Elaborating on the technology’s potential, Professor Joshua Edel from the Department of Chemistry at ICL 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.”
Additionally, this technology allows for better cataloguing of seemingly identical cells, which would help researchers better understand fundamental cellular processes and design improved disease models as well as patient-specific treatments.