A new diagnostic test for Sars has been developed by a team from the University of Hong Kong that can make it cheaper for developing countries to detect the disease quickly. The new test is based on recently developed molecular technology known as Lamp - Loop-Mediated Isothermal Amplification Assay - which relies on a simple water bath to look for the genetic material of the Sars coronavirus. Sars is currently diagnosed either by detecting antibodies against the coronavirus or by tests using polymerase chain reaction (PCR) which require sophisticated equipment costing several hundred thousand dollars. 'Because of the requirements for sophisticated instrumentation and expensive reagents, these rapid molecular tests might not be the method of choice in basic clinical settings in developing countries,' said Leo Poon Lit-man, an assistant professor in microbiology. He said the new test would be much cheaper than the PCR. A single Lamp test can cost $20 to $30 compared with a PCR costing at least $100. 'This would facilitate the preliminary screening for Sars in developing countries,' Professor Poon said. He said the test could be useful when an outbreak occurred in remote villages.