Biochip technology reveals fingerprints of biochemical threats

Argonne biochemist Daniel Schabacker could be considered a Sherlock Holmes of bioterrorism. Although he does not carry around a pipe and magnifying glass as he attempts to nab the culprit, he has a far more powerful deductive tool: the biochip.

The biochip offers Schabacker and his colleagues at Loyola University in Chicago a chance to determine the signatures of biological agents that can be used for bioterrorism, most notably the bacterium that causes anthrax, Bacillus anthracis. While some scientists have used DNA analysis to identify particular strains of the anthrax bacterium, the biochips help scientists and government officials learn how anthrax bacteria are grown, narrowing the pool of potential suspects. This project, started only within the past couple of years, exemplifies the burgeoning field of microbial forensics.

“Microbial forensics is one of the biggest topics in counterterrorism today, and one of the biggest challenges in dealing with bioterrorism,” Schabacker said. “The proteomic analysis that we’re able to perform with our biochips provides a new and different set of information about biological agents than we’d been able to see before; it can provide us with a complete fingerprint of the organism that we can then use to more precisely identify its origin.”

According to Schabacker, most efforts in microbial forensics today rely on DNA analysis for their findings. On its own, Schabacker said, DNA analysis may not be sufficient to give investigators all the information they need about a particular bioagent. “The problem with only using conventional DNA analysis is that it only tells you what strain you are dealing with, and strains used by the good guys can be obtained by our enemies. There can be dozens of labs that all share the same strain,” he said. “Our approach attacks the problem in a completely different way. We take advantage of the fact that unlike cellular DNA, bacterial proteins change dramatically when the growth or preparation of the bacterial culture is altered — and that information is incredibly important.”

Because the anthrax bacterium’s proteins hold a unique and detailed record of how the cells were generated and handled, Schabacker believes that pursuing DNA and protein analyses in concert could yield a comprehensive database that identifies the conditions used to prepare almost any B. anthracis culture. “The ultimate goal of this project is to build a library of ‘signatures’ of B. anthracis grown and