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Front Lines Researchers are developing several new MS methods and instruments to unambiguously identify biothreat agents. Katie Cottingham
© 2006 AMERICAN CHEMICAL SOCIETY
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hortly after the September 11, 2001, terrorist attacks, anthrax-laced letters were mailed to media organizations and to two members of Congress. According to news accounts, 5 people died and 17 people became ill after coming into contact with mailed Bacillus anthracis spores. Fear gripped the nation as authorities embarked on an international manhunt for those responsible. Nearly five years later, the crime is still unsolved. Although work on the detection and analysis of biothreat agents has been ongoing for decades, the 2001 anthrax attacks thrust the discipline into the spotlight in the U.S. and around the world. Researchers are actively developing detectors for the military and first responders, such as emerJ A N U A R Y 1 , 2 0 0 6 / A N A LY T I C A L C H E M I S T R Y
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With MS, one doesn’t need to determine ahead of time which microorganisms to look for.
gency medical technicians, police, and firefighters, who require small, rapid, sensitive, and selective detectors. Larger, more expensive instrumentation is typically needed for samples that are brought back to a laboratory for in-depth analysis, but the requirements for high sensitivity and specificity remain. The most common detection techniques used in the field and in laboratories are methods based on classical microbiology, PCR, and antibody techniques, according to experts. These techniques can be sensitive and selective; however, they are also very specific, and this can be a disadvantage. To culture a microorganism, for example, one must know which medium selectively allows the sampled pathogen to grow. For current PCR methods to be successful, primers must be carefully designed for the genome of a particular microorganism. Also, antibodies bind only to specific pathogen proteins. “There are tens, if not hundreds, of thousands of [pathogens] you have to worry about for biowarfare surveillance,” says Steven Hofstadler of Ibis Therapeutics. “You can’t have that many specific tests and ask 10,000 very specific questions to decide if something has been released into the air or water supply.” He adds that even if a special test for every known pathogen existed, newly emerging pathogens, such as the coronavirus that causes severe acute respiratory syndrome (SARS) and genetically altered biothreat agents, would be missed. With MS, however, one doesn’t need to determine ahead of time which microorganisms to look for. Robert Cotter of the Johns Hopkins University (JHU) School of Medicine says, “I think [MS] has the potential to be the most broadband detector of anything I can think of, because everything has masses.” The masses of proteins, lipids, carbohydrates, and metabolites can all provide information about the microorganisms in a sample. Even if an unknown organism is present, experts say that it can often be traced to a particular family on the basis of the masses of its constituent compounds. Many MS techniques are rapid and provide an answer in
