Biological Warfare, Advanced Diagnostics

Forensic analysis techniques are often used for other applications. For example, various chromatographic techniques can be used to examine an array of materials, including blood and other forensically-relevant samples.

Technologies that are used to detect biological warfare agents can be relevant to forensic analyses. These include the detection of living bacteria, based on the metabolic conversion of one compound to another by the organisms. Indeed, one novel technology can detect the distinctive aromas emitted by bacteria when they metabolize certain compounds.

Toxins that are produced by bacteria including Bacillus anthracis (the agent of anthrax) and Clostridium botulinum (which causes the food-borne illness of botulism) can be detected using antibodies targeted specifically for the particular toxin protein. Other poisons (such as ricin) are likewise detectable.

In the United States, the development of diagnostic capabilities for biological warfare is a government concern. The Advanced Diagnostics Program is funded by the Defense Advanced Research Projects Agency of the United States government (DARPA). Its objective is to develop tools and medicines to detect and treat biological and chemical weapons in the field at concentrations low enough to prevent illness. Challenges to this task include minimizing the labor, equipment, and time for identifying biological and chemical agents.

One area of interest includes development of field tools that can identify many different agents. To accomplish this goal, several groups funded under the advanced diagnostics program have developed field-based biosensors that can detect a variety of analytes, including fragments of DNA, various hormones and proteins, bacteria, salts, and antibodies. These biosensors are portable, run on external power sources, and require very little time to complete analyses.

A second focus of the advanced diagnostics project is the identification of known and unknown or bioengineered pathogens and development of early responses to infections. Many viruses act by destroying the ability of cells to replicate properly. One group funded under the advanced diagnostics program is studying the enzyme inosine 5′-monophosphate dehydrogenase (IMPDH), which produces products that are required for synthesizing nucleic acids, such as RNA and DNA, both of which are essential for proper cell replication. This group seeks to develop novel drugs based on IMPDH, which can cross into cells and thwart viral infection.

A final goal is to develop the ability to continuously monitor the body for evidence of infection. Researchers are addressing this goal in two ways. The first involves engineering monitoring mechanisms that are internal to the body. In particular, groups funded under the initiative are developing bioengineered white blood cells to detect infection from within the body. Often genetic responses to infection occur within minutes of infection, so analysis of blood cells provides a very quick indication of the presence of a biological threat. The second method involves the development of a wearable, non-invasive diagnostic device that detects a broad-spectrum of biological and chemical agents.