Swiss scientists say they have found a fast and simple way to test for deadly anthrax.
Anthrax has been used as a bioweapon against civilians
Diagnostic tests already exist but are expensive and time-consuming - and time is critical since anthrax infection can kill unless treated within 24 hours.
The new test targets a molecule unique to anthrax, which is found on its surface, to give a result in minutes rather than days or hours.
The work by the team at Bern University is published in Angewandte Chemie.
Simple and fast
The spate of US anthrax attacks in October 2001 highlighted the need for fast and reliable ways to diagnose of anthrax.
Indeed a month later, US scientists developed a test that could confirm the presence of anthrax in just under an hour by analysing the genetic material of the bacteria.
Prior to that it had taken days to confirm the presence of anthrax in human and environmental samples.
But scientists have been looking at ways to test results even faster and have been investigating immune techniques to this end.
Previous attempts at developing a fast anthrax tests using the same immunological technology as the new Swiss test failed because the targets used were not specific enough.
The similarity of anthrax's surface to those of other bacteria found in humans had been a major stumbling block.
Immunological tests work by detecting or quantifying a specific substance in a sample using an immunological reaction between things called antibodies and antigens, and can give results in minutes.
Their high specificity results from the use of antibodies - proteins produced by the body's defence cells in response to a specific foreign invader or antigen.
Professor Peter Seeberger and his team at Bern first set out to create antibodies against the anthrax surface molecule.
In order to do this, it is necessary to have a large enough amount of the molecule. However, it has been exceptionally difficult to isolate the anthrax surface molecule in its pure form.
To get round this, Professor Seeberger's team made an artificial version of the molecule in the laboratory. They then attached this molecule to a special carrier protein and injected it into mice.
The mice mounted an immune response to the injection, as the researchers had planned. The scientists were then able to obtain antibodies from the mice that were specific for the anthrax surface molecule.
The scientists believe these antibodies could be used to make a highly sensitive test for anthrax. In the future, it might also be possible to develop new anthrax vaccines with the antibodies.
Professor Seeberger explained: "Our results demonstrate that small differences in the carbohydrates on cell surfaces can be used to obtain specific immune reagents."
He said these could be used to make a simple, cheap and quick test for anthrax, which he envisages could be available in under a year.
"This is something that anyone dealing as first responders to potential anthrax threats - post offices, police forces and the military - could use."
A scientific spokesman for the National Institute for Biological Standards and Control said the research looked promising, but stressed that more work was still needed.
"It holds promise for the development of a very specific and fast anthrax detection method," he said.
Anthrax investigator Jim Uhl, from the Mayo Clinic, Rochester, the US, said: "This is a very important first step."
He said currently there were no tests available that could check for anthrax in under an hour.
He added: "Tests like this might have great utility for cities that are testing the air. People could develop assays that could sit on top of buildings and sniff out the air for anthrax."