15. Fluorescing DNA Nanobarcodes
Dan Luo, Biological and Environmental Engineering, and his research team created synthetic DNA barcodes, molecular tagging devices, that fluoresce under ultraviolet light in a combination of colors that can be read by a computer scanner or observed with a fluorescent light microscope. The researchers wanted to provide an inexpensive method of identifying biological molecules that can be used with readily available equipment. The idea is based on an application the researchers found for dendimer-like DNA, which consists of many short strands of Y-shaped DNA linked together in a treelike structure. Ignoring the DNA’s genetic coding properties, Luo’s research uses DNA as a generic instead of a genetic material. His research team synthesized three short strands of DNA, each of which is complementary to one of the others along half its length, in order to create the Y-shaped structure. Combining several of these structures creates a web with branching loose ends of DNA, to which an antibody that will bind to the molecule to be detected is attached, while molecules of fluorescent dye are attached to the other ends. Up to 1,000 different codes can be created using only three fluorescent dyes. The nanobarcode detection system does not require complex preparation of a sample and can be applied to living cells. The technology could be used in genomic research, clinical diagnosis, drug testing, environmental monitoring, and monitoring for biological terrorism.