Microfluidic picoliter droplet reactors for gene analysis and synthesis

In the past decay, the completion of the Human Genome Project opens a door for the emergent development of genetic related researches. It includes genotyping for genetic related diseases discovery, genetic therapy by RNA interference, and etc. To develop techniques which can rapidly analyze multiplex genes in ultra low concentration in small volume of samples is always demanded. The intrinsic property of microfluidic system has the unique low Reynolds number fluids and laminar flows. These microfluidic properties result in the advantages to manipulate small volume of liquid easily. Microdroplet in microfluidic channel can be a separated and individual micro-reactor, it can further improve the sample dispersion and contamination problems which are often seen in continuous microfluidic system.;We developed Laminar Flow And Microdroplet (LFAM) based platform for in situ fast SNR optimization by co-localizing MB (Molecular Beacon), DNA samples, Mg2+ and K+ in monodispersed picoliter droplets. It does not require repetitive loading and the results are immediate. Label-Free DNA Analysis in Microdroplet (LFDAM) was developed to rapidly detect DNA and its mutants in microfluidic droplets, in addition to elucidating the dynamic hybridization process. The MB-DNA duplex formation process was acquired by the time-resolved method: converting distance traveled to hybridization time. This technique demonstrates the ability to detect multiplex genes within few seconds in microdroplet, and distinguish single nucleotide polymorphisms (SNPs). Cationic liposome based vector for gene delivery is a novel carrier for non-viral gene transfection. However, it has drawbacks in low transfection rate and high variation in transfection efficiency. The Picoliter Microfluidic Reactor and Incubator (PMRI) system developed in this dissertation is able to control these parameters in order to demonstrate that the gene transfection efficiency of lipoplex is more reproducible. A Y-junction based 128-channel microdroplet generation platform to split one primary droplet into 128 monodispersed daughter droplets was also developed for monodispersed picoliter droplet mass production.;Hence, the laminar flow and microdroplet (LFAMD) system, rapid label-free DNA analysis in microdroplet (LFDAM), and picoliter microfluidic reactor and incubator (PMRI) systems demonstrated in this dissertation are novel and promising methods to improve gene analysis and gene synthesis.