A detection chip for spotting bird flu in remote geographic areas could become a reality, claim scientists in Singapore. A group led by Pavel Neuzil at the Institute of Bioengineering and Nanotechnology has developed a device to amplify DNA that they expect to become a central part of a lab on a chip system.

The polymerase chain reaction (PCR) is used to multiply pieces of DNA in a sample using a repeated cycle of heating and cooling. Conventional lab based PCR equipment is bulky and slow, with large reaction tubes that make the process expensive. Neuzil has made a microPCR device that uses small (1?l) reaction samples placed on disposable glass slides, minimising contamination and reducing costs. Its small size means that the device can heat and cool the reaction quickly, which reduces the amount of by-products formed. Also, less power is needed to heat the smaller samples and Neuzil plans to exploit this by building a portable battery operated system.

A potential use for the device is in identifying diseases, such as bird flu, in remote areas, said Neuzil. Currently the detection process can take several days as samples are transferred to central laboratories. 'Using an on-site simple PCR system would speed up the whole process and help identify an infection outbreak,' Neuzil explained.

Eric Lagally of the University of California, Santa Barbara, US applauds the work. The approach 'is an important step toward a microfluidic, portable PCR-based diagnostics system,' said Lagally.

Laura Howes