The miniaturisation of electronics led to the silicon chip and the revolution in computing. Researchers are now adopting the same approach to the medical laboratory. By miniaturising and integrating processes normally performed by a full-scale laboratory onto devices just a few centimetres across, they are creating labs-on-chips that can diagnose and monitor diseases ranging from cancer to HIV. Labs-on-chips or LOCs would be cheap to manufacture, easy to operate and sit in every GP surgery. They would be used to detect bacteria and viruses, analyse blood samples, or detect contamination in food and water samples. According to researchers, LOC devices will greatly improve diagnostics and help us live healthier lives. They may eventually become as ubiquitous as microelectronic chips and lead to personalised medicine, where LOCs in your bathroom cabinet will tell you, instantly, whether that runny nose is a symptom of the common cold or swine flu.