Chemists in Ireland have developed a device that can measure the breath of tiny embryos.

Dmitri Papkovsky and colleagues at University College Cork built a microchip that monitors the oxygen used by mouse embryos at the very earliest stages of their development, when they are only a few cells in size.

The team hope the chip will prove useful for monitoring the health of embryos created by in vitro fertilisation (IVF), a process whereby eggs are extracted and fertilised outside the body and the successfully fertilised eggs are implanted into the womb later. IVF is used to help infertile couples conceive, as well as being a useful tool in animal breeding programmes.

'Multiple births and unsuccessful attempts are commonplace in the field of IVF,' said Papkovsky. He ascribes this to a lack of understanding of the factors that make a healthy embryo. The rate at which embryos consume oxygen is a good indicator of their health, but because very early embryos use such tiny amounts of oxygen, this can be hard to measure. Papkovsky's chip uses a molecule that fluoresces when oxygen is removed in order to provide a sensitive measurement of how quickly the oxygen is used up.

'This work shows the importance of taking an integrated view of sensing devices to combine advances in both chemistry and engineering to meet real needs,' said Tony Turner, professor of biotechnology at Cranfield University, UK. 'Developments in biochips are now reaching the stage where they have exited the research lab and are finding real utility in clinically relevant situations,' he added.

Although the chip can only currently measure embryos in batches of ten, Papkovsky sees monitoring of individual embryos as an achievable goal. 'We see moving towards use in routine analysis in IVF clinics as the way forward for this work,' he said.

Clare Boothby