In 2002, the Defense Advance Research Projects Agency (DARPA) funded an initiative to research the use of magnetic technologies in the detection, manipulation and control of cells, molecules and nanomolecules called Bio-Magnetics Interfacing Concepts (BioMagnetICs). Living cells and biological molecules are not particularly polar, therefore using magnetic markers as tags represents a highly specific and easily detectable signal for measuring cellular response to environmental conditions, including the presence of biological and chemical toxins. The function of cells and tissues are, to a large extent, managed by the flow of chemical information across membranes via membrane receptor molecules. These membrane receptors are extremely specific, controlling exactly which molecules pass in and out of the cell and at what rate. DARPA's bio-magnetics program seeks to exploit these molecular functionalities by building stable, accurate and sensitive sensors that detect and monitor cellular functions such as protein synthesis, DNA expression, cell death and pigment generation.
The BioMagnetICs program has three major goals. First, it hopes to develop new magnetic tags, or ferrofluids, which have a strong magnetic signal and which can be attached to specific cells and biological molecules. Second, research within the BioMagnetICs program will focus on developing highly sensitive magnetic tags for attachment to fragments of molecules with diameters less than 100 nm within living cells. The final objective of the BioMagnetICs program is to develop magnetic tweezers that can manipulate single molecules and fragments of molecules with precision on the order of nanometers.
One of the expected technologies resulting from the BioMagnetICs program includes bio-detection devices that can detect several different analytes very quickly and with minimal preparation of samples. These magnetic readers have the capacity to provide 10 to 1000 times more sensitivity than is possible using current analysis techniques. In addition, these devices are expected to detect toxins with a specificity that is greater than 99%. Because biological and chemical toxins can be dangerous in extremely low concentrations, speed, sensitivity and specificity are extremely important for ensuring the safety of troops in regions where weapons of mass destruction may play an important role.
█ FURTHER READING:
Defense Advanced Research Projects Agency, Defense Sciences Office < http://www.darpa.mil/dso/thrust/biosci/biomagn.htm > (March 20, 2003).