Golden Standard: A complete standard, portable, and interoperative MoClo tool for model and non-model bacterial hosts.

Modular cloning assembly has become a benchmark technology in synthetic biology. However, there is a mismatch between its impressive development and the standardization required to promote interoperability between the different systems available. The full development of the field is thus hampered by a surge of oftentimes incompatible organism-specific systems. To overcome these issues, we present Golden Standard (GS), a Type IIS assembly method underpinned by the Standard European Vector Architecture (SEVA). GS unlocks modular cloning applications for most bacteria, and delivers consistent combinatorial multi-part assembly of standardized genetic elements to create genetic circuits of up to twenty transcription units. Reliance on the Modular Cloning (MoClo) syntax renders GS fully compatible with many existing tools and it sets the path towards efficient reusability of available part libraries and assembled TUs. GS was fully validated in terms of DNA assembly performance, portability and phenotype engineering in model and non-model bacteria. In order to facilitate the widespread adoption and future community-driven development of GS, we provide a web-portal featuring: i) a repository of parts and vectors, ii) Wizard and Setup tools to guide the design of constructs using stored and user-specific parts. ### Competing Interest Statement The authors have declared no competing interest.