A microfluidic SELEX prototype.

Aptamers are nucleic acid binding species capable of recognizing a wide variety of targets ranging from small organic molecules to supramolecular structures, including organisms. They are isolated from combinatorial libraries of synthetic nucleic acid by an iterative process referred to as SELEX (Systematic Evolution of Ligands by Exponential Enrichment). Here we describe an automated microfluidic, microline-based assembly that uses LabView-controlled actuatable valves and a PCR machine, and which is capable of the selection and synthesis of an anti-lysozyme aptamer as verified by sequence analysis. The microfluidic prototype described is 1) a simple apparatus that is relatively inexpensive to assemble, making automated aptamer selection accessible to many investigators, and 2) useful for the continued "morphing" of macro-->meso-->microfabricated structures until a convergence to a few functional systems evolves and emerges, partly or completely achieving simpler, smaller and more rapid SELEX applications.