Optical tweezers-directed parallel DNA synthesis in laminar flow microreactors

Microfluidic reactors have been recognized as ideal platforms for chemical reactions due to several advantages, including fast reaction kinetics, fast diffusion and heat transfer, low reagent consumption and short processing time. Applications combining microfluidic reactors with standard solid-phase synthetic chemistry have recently emerged to synthesize DNA oligomers. They generally suffer from limited sequence output---one sequence per reactor. In this thesis, I developed an optical tweezers directed approach that allows synthesis of different oligonucleotide on an array of controlled porosity glass (CPG) beads in parallel in a two-stream laminar flow microreactor and obtained one oligo sequence per bead. These reactors have been shown to effectively facilitate CPG bead loading and confinement, maintain liquid/liquid (inert liquid/reagent) interface and withstand the reagents and solvents present in the modified phosphoramidite chemistry. The optical trapping force and trap stiffness were characterized with drag force method on both solid glass and CPG beads. I demonstrated that the CPG beads could be moved within the synthesis microreactors from one mechanical holder to another, as required in this application. The parallel synthesis of several different oligonucleotides in a single synthetic run was successfully demonstrated with fluorescence in-situ hybridization (FISH) detection. The oligonucleotides include sequences of target 25mer, one deletion, one substitution, and control group. This universal approach is also applicable to other biological and biochemical systems that require parallel processing and sensing with multiple solid beads.