Dr. Ellington's research focuses on using evolutionary techniques to engineer biopolymers and cells. His co-researchers select binding species(aptamers) and ribozymes from random sequence populations, and then attempt to apply the selected species to solve real-world problems. For example, we have selected aptamers that can interact tightly and specifically with the Rev protein of HIV-1, and are exploring how these aptamers can be used to block viral replication. Similarly, we have selected ribozymes that can be allosterically activated by oligonucleotide effectors, and are using these ribozymes to design and build biosensors that may be useful in diagnosing disease. We also have developed methods for evolving proteins with novel functions, and are similarly attempting to use the evolved proteins in medical or biotechnological applications. For example, we are working on isolating stable variants of p53, a protein whose deficiency is frequently implicated in the onset of cancer. Stable p53 variants might be used in gene therapies for cancer patients. Finally, we have extended our evolutionary approaches to whole organisms, and are attempting to evolve 'unnatural' E. coli (unColi) that can augment their genetic codes with unnatural amino acids. It is hoped that strains of unColi will allow us to generate enzymes with previously unknown or unaccessible structures or activities.