Along with purified targets, we also have significant experience selecting aptamers against the surface of whole cells. With funding from the National Science Foundation, our scientists partnered with a biotechnology company to develop an inexpensive DNA aptamer mimetic for a so-called stem cell factor (SCF or “kit ligand”).
Recombinant SCF is an expensive but commonly used reagent in stem cell culture.
To achieve this goal, we enriched our randomized DNA library for aptamers that bound whole stem cells. Our scientists then selectively displaced the desired aptamers from the c-Kit receptor using real SCF. Although we were unable to evolve an agonist mimetic (to effect stem cell proliferation in culture), we successfully developed a number of candidate c-Kit specific antagonists. We are currently quantifying their affinity.