Cell-SELEX is a live cell-based in vitro selection method that generates functional oligonucleotides, or aptamers. Often referenced as the chemist's antibody, aptamers bind to select targets with high affinity and can be utilized in a number of applications, including biomedicine, bioimaging, and biosensing. Here we describe the cell-SELEX technique and discuss this methodology's unique merit(s)-namely the ability to isolate highly selective aptamer panels with no prior knowledge of cellular signatures. This strategy thus presents as a technology that has the potential to enhance the precision of molecular medicine and targeted therapeutics.