Researchers have developed a cheap, fast and simple way of diagnosing two forms of the liver disease hepatitis.
They say that while existing methods of detecting the hepatitis virus are effective, they are costly, time-consuming and can only be done by skilled people in a laboratory setting.
The new approach uses a 'protein chip', a small, portable device that makes it easy to find specific proteins in a blood sample.
It could make it easier to diagnose and treat both forms of the disease in developing countries, where they are most problematic.
The researchers, led by Yefu Wang of China's Wuhan University, created a protein chip that detects the B and C strains of the hepatitis virus in blood samples by recognising 'antibodies' that people produce in response to infection.
The chip is a small piece of glass coated with viral proteins. When blood from a patient infected with the virus is added to it, the antibodies stick to the viral proteins.
The chip also contains tiny gold particles that are engineered to stick to the antibodies and makes them visible to the naked eye.
These remain after the chip is washed, indicating that the patient is infected by the hepatitis virus.
According to the research, published online by BMC Infectious Diseases on 6 July, the method produces results in just 40 minutes.
Wang's team add that it is just as effective as existing but costly and time-consuming ways of diagnosing hepatitis.
"It is a technology tailored for developing countries' needs at both technical and economic levels," says Abdallah Daar, co-director of the Canadian Program on Genomics and Global Health at the University of Toronto, Canada.
Daar told SciDev.Net that there is a great need for simple and inexpensive technologies for diagnosing and monitoring infectious diseases in developing countries. He added that the protein chip approach could be used to create diagnostic tests for other infections such as HIV/AIDS.
Hepatitis B is a leading cause of liver cancer.
Reference: BMC Infectious Diseases 5, 53 (2005) doi: 10.1186/1471-2334-5-53