This Small Business Innovation Research (SBIR) Phase I research develops an efficient method to produce single-stranded DNAs, known as aptamers, which can bind to receptors on the surface of cells and mimic the biological effects of naturally occurring proteins that bind to these receptors. These proteins control cellular functions and are critically important for the emerging applications of stem cells for therapeutics. These proteins are often difficult to produce and expensive, whereas aptamers are relatively easy to make and cheap. In phase I, aptamers will be produced which mimic the effect of a protein known as stem cell factor (SCF). Stem cell factor has been identified as a key protein in stimulating stem cell growth. A procedure known as SELEX (Systematic Evolution of Ligands by Exponential Enrichment) will be used to identify aptamers from a large pool of such molecules that bind to all receptors on the surface of stem cells. A new procedure will be used to pinpoint aptamers which bind only to the targeted SCF receptors and produce a biological response.<br/><br/>The broader impacts of this research are 2-fold. First, this technology will replace rare and expensive proteins with abundant and cheap aptamers that mimic the biological effects of these proteins, enhancing basic research applications. Second, these aptamers have the potential to replace many therapeutic proteins now on the market or yet to be developed, contributing significantly to the reduction of healthcare costs in the future.