Systematic Evolution of Ligands by Exponential Enrichment (termed SELEX) is a combinatorial technique for producing high affinity oligonucleotides (aptamers) of either DNA or RNA that specifically bind to a variety of target ligands, including small molecules, proteins, tissues and organisms. In previous work, we demonstrated a high efficient SELEX platform for rapid generation of aptamers through a microfluidic separation device under a high stringency selection condition. In this work, we significantly extend the capability of M-SELEX method from a rapid evolution of high affinity aptamers to a development of high molecular specificity of the selected aptamers via microfluidic negative selection.
