Researchers at MIT Lincoln Laboratory developed a portable mobile detector of airborne pathogens such as anthrax spores. The device, called PANTHER (for PAthogen Notification for THreatening Environmental Releases), is only one cubic foot in size and weighs 37 pounds. The technology behind the device is a bioelectronic sensor called CANARY (for Cellular Analysis and Notification of Antigen Risks and Yields), that utilizes genetically engineered B cells and a photon detector.
The article Rapid Sensors for Biological-Agent Identification (.pdf) by Martha S. Petrovick, et al. in November 1007 issue of Lincoln Labarotory Journal explains the biologically inspired CANARY technology:
Our technology is based on genetically engineered B cells, a type of white blood cell that binds to and recognizes pathogens quickly and assists other parts of the immune system to fight the infection. B cells are the fastest pathogen identifiers known (intrinsic response in <1 second). We have modified them to bind specifically to the pathogens of interest and within seconds emit photons to report that the binding event has occurred. Two routine genetic modifications enable engineered B-cell lines to express cytosolic aequorin, a calcium-sensitive bioluminescent protein, as well as membrane-bound antibodies specific for pathogens of interest. The crosslinking of membrane-bound antibodies by a polyvalent antigen induces a signal-transduction cascade that sequentially involves tyrosine kinases, phospholipase C, and inositol triphosphate (IP3). IP3 activates calcium channels, thereby increasing cytosolic calcium from both internal stores and the extracellular identification medium, which activates the aequorin, causing it to emit light. This sensor concept, shown in Figure 2, which we call CANARY, can detect <50 colony-forming units (cfu) of pathogen in less than 3 minutes, including the time required to concentrate the samples. In contrast, even state-of-the-art immunoassays take at least 15 minutes and have a much higher limit of detection. While the polymerase chain reaction (PCR) can be both highly specific and sensitive, most reports cite protocols that take longer than 30 minutes. An ultrafast PCR with detection of 5 cfu in only 9 minutes has been reported. However, even when coupled with the most rapid sample-preparation technology the total assay requires 20 to 30 minutes to complete. Because of its unique combination of speed and sensitivity, CANARY has important benefits for pathogen identification in medical diagnostics, biowarfare defense, and other applications. We have developed a genetic-engineering system that allows efficient production of B-cell lines that react specifically and rapidly to a variety of pathogens. Antibody genes cloned from hybridomas (cell lines that produce a single monoclonal antibody) are inserted into expression vectors. These vectors are transfected into a parental B-cell line that expresses active aequorin, and the cells are screened for their response to pathogen. These genetically engineered CANARY cells can be used separately in a single identification assay, or as many as three can be combined to achieve a multiplexed assay. Alternatively, several antibodies can be expressed in a single cell line to provide a classification assay. It is also feasible to create B cells that emit at different wavelengths of light, enabling multiplexed assays that simultaneously distinguish among several targets.