No abstract

We present a droplet-based microfluidic system that enables CRISPR-based gene editing and high-throughput screening on a chip. The microfluidic device contains a 10 × 10 element array, and each element contains sets of electrodes for two electric field-actuated operations: electrowetting for merging droplets to mix reagents and electroporation for transformation. This device can perform up to 100 genetic modification reactions in parallel, providing a scalable platform for generating the large number of engineered strains required for the combinatorial optimization of genetic pathways and predictable bioengineering. We demonstrate the system’s capabilities through the CRISPR-based engineering of two test cases: (1) disruption of the function of the enzyme galactokinase (galK) in E. coli and (2) targeted engineering of the glutamine synthetase gene (glnA) and the blue-pigment synthetase gene (bpsA) to improve indigoidine production in E. coli.

Poly(methyl methacrylate) thin films were prepared through solvent casting method followed by thermal treatment to completely remove the residual solvent. All three different tactic PMMAs were studied; the PMMA solution was made in chloroform at various concentrations, with 0.1wt% QDs added against the polymer mass in the polymer solution. PMMA-QDs thin films as well as the pristine PMMA thin film (as control sample) were characterized using a variety of analytical techniques to probe their structure, functionalities, and respective physicochemical properties including thickness, surface wettability, fluorescence emission, and biocompatibility using HeLa mammalian cell as a model cell line. The fluorescence emission steadily increased when the concentration of PMMA increases. The wettability test showed i-PMMA to be more hydrophilic with a smaller contact angle than the other tacticity, while a-PMMA showed to be more hydrophobic with a larger contact angle than the other tacticity. All PMMA-QDs thin films used in co-culturing with HeLa cells supported their growth and proliferation.

We present a droplet-based microfluidic system that enables CRISPR-based gene editing and high-throughput screening on chip. The microfluidic device contains a 10 x 10 element array, each element containing sets of electrodes for two electric field actuated operations- electrowetting for merging droplets to mix reagents and electroporation for transformation. It can perform up to 100 genetic modifications in parallel, providing a scalable platform for generating the large number of engineered strains required for combinatorial optimization of genetic pathways and predictable bioengineering. We demonstrate the system's capabilities through CRISPR-based engineering of two test cases- 1) disruption of the function of enzyme galactokinase (galK) in E. coli and 2) targeted engineering of glutamine synthetase gene (glnA) and blue-pigment synthetase (bpsA) enzyme to improve indigoidine production in E. coli.