An electric pulse is used to create pores in single cells held in a microfluidic device
Stem cells have generated considerable interest among medical scientists as modified stem cells offer a potential route to treat diseases using cell therapy. However, the cells are often found in very low numbers and are difficult to isolate, so it is important to be able to modify them efficiently. Standard techniques include bulk electroporation, in which an electrical pulse is applied to cell suspensions to create pores in the cell membranes. Yet these are not particularly effective, with typically only 1-11 per cent of stem cells taking up DNA through the pores.
To improve the DNA take-up, or transfection, rate, Albert van den Berg and Ana Valero at the University of Twente, in Enschede, The Netherlands, and their co-workers have developed a system for transferring DNA into stem cells held in a microfluidic device. In this process individual cells are immobilised in mechanical traps and electroporated to transfer DNA into the cells. The added DNA encodes a fluorescent protein which is expressed, demonstrating that the DNA is still biologically viable. The transfection rate was high, with over 75 per cent of cells producing the protein, which van den Berg attributes to the system's 'very well controlled environment.' Looking to the future, van den Berg said the team hoped to create 'a tool for biologists to study and further develop cell reprogramming.'
Huabing Yin, an expert in applying microfluidic techniques to study biological systems, from the University of Glasgow, UK, welcomed the research. 'It demonstrates an efficient way of achieving gene transfer in a single stem cell,' said Yin, 'and is an excellent example of microfluidic applications in life science.'
Source: Reprinted with permission from Chemistry World (Russell Johnson)