Anyone listing key technologies for the next century would put genomics and computer chips near the top. Recently the two have been brought together, in the form of DNA chips or gene chips - a combination that is poised to revolutionise medical research and diagnois. In the US, both President Clinton and Vice-President Al Gore have recently cited DNA chips as prime example of the power of science to improve human health. Researchers are already beginning to use them to distinguish between different forms of cancer and strains of HIV.