APEX: Automated Protein EXpression inEscherichia coli

Abstract

AbstractHeterologous protein expression is an indispensable strategy to generate significant amounts of recombinant proteins. To this end,Escherichia coli(E. coli) is one the most used microbial host for recombinant protein production due to its rapid growth, well-characterised genetics, and ability to produce recombinant proteins in high yields using modern recombinant DNA technology. However, while there is a plethora of robust protein expression protocols forE. coli, these methods are often unsuitable for high-throughput screening due to their significant resource and time consumption; these protocols are also susceptible to operator error and inconsistency.To address these challenges, we have developed APEX, a robust and automated protocol for recombinant protein production inE. coli. APEX leverages the accessible, open-source Opentrons OT-2 platform to automate microbial handling and protein expression with high precision and repro-ducibility. APEX can be configured to perform heat shock transformation, colony selection, colony sampling, inoculation, subculturing and protein expression using a low-cost, minimal OT-2 hardware setup. We further demonstrate the efficacy of our automated transformation workflows using a variety of plasmids (2.7-17.7 kb), and exemplify the automated heterologous expression of a diverse array of proteins (27-222 kDa). Designed with customization, modularity and user-friendliness in mind, APEX can be easily adapted to the operator’s needs without requiring any coding expertise.APEX is available athttps://github.com/stracquadaniolab/apex-nfunder the AGPL3 license.