DNA is primarily known as carrier of genetic information, the blueprint of life. DNA, however, is more versatile than that. Short DNA molecules can bind other molecules, even if these molecules not naturally interact with DNA. Such a DNA molecule, that is capable of specifically binding another molecule, is called an aptamer.
Because aptamers can bind a wide vartiy of targets there are numerous applications, varying from medicine to toxin detection. There are billions of different DNA molecules, but only a few are useful aptamers; the main challenge is to find them. In this research, several streptavidin-binding aptamers have been identified. Furthermore, this research shows that small changes in the composition of the aptamer can completely abolish its target-binding capacity. These, and other findings, could contribute to more effective aptamer selection procedures.