FRAGLER: A Fragment Recycler Application Enabling Rapid and Scalable Modular DNA Assembly.

Rapid and flexible plasmid construct generation at scale is one of the most limiting first steps in drug discovery projects. These hurdles can partly be overcome by adopting modular DNA design principles, automated sequence fragmentation, and plasmid assembly. To this end we have designed a robust, multimodule golden gate based cloning platform for construct generation with a wide range of applications. The assembly efficiency of the system was validated by splitting sfGFP and sfCherry3C cassettes and expressing them in E. coli followed by fluorometric assessment. To minimize timelines and cost for complex constructs, we developed a software tool named FRAGLER (FRAGment recycLER) that performs codon optimization, multiple sequence alignment, and automated generation of fragments for recycling. To highlight the flexibility and robustness of the platform, we (i) generated plasmids for SarsCoV2 protein reagents, (ii) automated and parallelized assemblies, and (iii) built modular libraries of chimeric antigen receptors (CARs) variants. Applying the new assembly framework, we have greatly streamlined plasmid construction and increased our capacity for rapid generation of complex plasmids.