Have you ever heard of DNA-based nanobarcodes? Actually, one day they might be able to cheaply identify biological molecules. From Cornell University press release:
A supermarket checkout computer can identify thousands of different items by scanning the tiny barcode printed on the package. New technology developed at Cornell University could make it just as easy to identify genes, pathogens, illegal drugs and other chemicals of interest by tagging them with color-coded probes made out of synthetic tree-shaped DNA.
A research group headed by Dan Luo, Cornell assistant professor of biological engineering, has created “nanobarcodes” 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…
To see how the technology works through Y-shaped DNA, go to the press release…