Researchers at the University of Gothenburg in Sweden have developed a new method to study single cells while exposing them to controlled environmental changes.
The method uses a set of laser tweezers to move the cell around in a microscopic channel system, allowing the researchers to study how single cells react to stress induced by a constantly changing environment.
Studies on how cells react to changes in their environment, such as reduced availability of nutrients, have traditionally used cultures consisting of millions of cells.
While such studies show how cells react on average to a new environment, they say nothing about individual variation, for example how quickly a single cell responds.
Emma Eriksson and her colleagues at the University of Gothenburg’s department of physics developed a method where laser tweezers are used to catch a cell of about 1um in size, and then move the cell between different environments.
Placing the cell in a system of channels made of silicone, in which each channel is finer than a human hair, enables the researchers to add and remove substances so that the environment surrounding a single cell changes in a split second.
At the same time, the researchers watch the reactions through a microscope.
The channels in the microfluidic system can be likened to tiny water pipes.
In a channel, a single cell can be exposed to tests and various substances for very exact time periods, which enables the researchers to repeatedly add and remove a substance to see how it affects the behaviour of the cell.
This method gives researchers information that would not be possible to obtain with traditional methods.
In its first stage, the method has been tested on yeast cells.
One of the cell’s proteins was tagged with a green fluorescent protein (GFP), enabling researchers to trace the movements of the protein within the cell while it adjusts to a new environment.
‘The method can be used to reveal how a cell reacts to stress induced by a change in its environment,’ said Eriksson.
‘The information gained from this may eventually lead to a better understanding of how cells work and what they do to stay alive and healthy in a constantly changing environment.’