To develop an aptamer screen, the researchers begin with a small amount of a purified protein from a particular cell type under particular conditions. That protein is used to select an aptamer from a pool, and the aptamer is eventually incorporated into an array with others that bind different proteins in that cell type, forming a unique protein signature. "The idea is that the pathology of tumors and other conditions will show changes in proteins in the blood, so that simple blood tests can be done routinely, for early warnings," says Gold, who with Craig Tuerk developed aptamer technology at the University of Colorado, Boulder, in 1989.1
Gold and Tuerk used an in vitro selection and evolution method called SELEX (systematic evolution of ligands by exponential enrichment) to investigate RNAs that bind bacteriophage T4 DNA polymerase. From there, the budding technology wound its way through a trajectory of biotech companies--to ...
