Principal Scientist, Microbial Expression Systems

RXinsider LTD.; Norwood (MA); On-site; USD 143,000 - 257,000; Full time

Benefits offered by this job

Best-in-class healthcare coverage

Well-being resources

Generous paid time off

Location-specific perks

Job summary

Moderna is seeking a Principal Scientist, Process Development (Expression Systems) to lead host strain, vector, and expression-system strategy for E. coli-based production of recombinant enzymes and plasmids.

You will design screening cascades and define decision criteria to drive scalable, robust upstream processes. The role requires deep expertise in microbial genetics, molecular biology, and synthetic biology, with experience translating small-scale screening outputs into development-ready

Qualifications

• PhD in Molecular Biology, Microbiology, Chemical/Biochemical Engineering, Biotechnology, Synthetic Biology with 5+ years of industry experience; or MS with 10+ years; or BS with 12+ years of industry experience.
• Substantial industry experience with E. coli strain engineering, vector design, expression-system development, or microbial production screening.
• Hands-on expertise developing and executing microbial expression-screening workflows for recombinant proteins, enzymes, plasmids, or related biological products.
• Strong understanding of E. coli genetics, physiology, metabolism, plasmid biology, expression regulation, and genetic stability.
• Experience designing and interpreting experiments that connect host/vector/expression choices to titer, yield, quality, robustness, and manufacturability.
• Experience with small-scale or high-throughput screening systems and translation of screening data into process-development decisions.
• Demonstrated ability to lead complex technical projects, influence stakeholders across functions, and communicate clearly through technical writing, data analysis, and presentations.

Responsibilities

• Own the strategy for E. coli host strain, vector, and expression-system for recombinant enzymes, plasmids, and related biological materials.
• Design and execute screening cascades that identify production candidates with strong titer, yield, quality, genetic stability, robustness, and process-development potential.
• Define stage-appropriate decision criteria for host/vector selection, expression tuning, induction strategy, plasmid stability, growth, product quality, and manufacturability.
• Develop and optimize small-scale and high-throughput screening workflows, including shake flask, deep-well plate, ambr, or other scale-down systems where appropriate.
• Evaluate host strains, promoters, ribosome binding sites, copy number, plasmid architecture, induction systems, codon/design strategies, secretion or localization strategies where relevant, and expression timing.
• Use DOE and data-driven approaches to improve screening throughput, predictiveness, reproducibility, and translation to bioreactor performance.
• Lead or support strain and vector engineering to improve expression performance, stability, productivity, robustness, and manufacturability.
• Apply molecular biology, microbial physiology, and synthetic biology principles to troubleshoot poor expression, instability, toxicity, metabolic burden, inclusion body formation, degradation, or inconsistent performance.
• Define fit-for-purpose characterization and handoff packages for candidate strains and constructs, including strain/vector history, design rationale, screening data, stability observations, known risks, and recommended development paths.
• Partner with process development, analytical development, downstream purification, informatics, automation, and data science teams to ensure screening outputs are actionable and linked to relevant quality and process attributes.
• Develop platform approaches and standardized documentation, data capture, decision criteria, and knowledge-management practices for recurring enzyme, plasmid, or microbial production needs.
• Support cross-functional troubleshooting, technical reports, development summaries, CMC-supporting documentation, and regulatory responses as needed.
• Serve as a technical leader and mentor in microbial genetics, molecular biology, expression-system design, screening strategy, and data interpretation.

Skills

Microbial genetics

Molecular biology

Expression-system design

Screening workflows

DOE/data-driven approaches

Technical leadership

Education

PhD in Molecular Biology, Microbiology, Chemical/Biochemical Engineering, Biotechnology, Synthetic Biology

MS with 10+ years of industry experience

BS with 12+ years of industry experience

Tools

Ambr

Shake Flask

High-throughput screening systems

Job description

Moderna is seeking a Principal Scientist, Process Development (Expression Systems) to lead host strain, vector, and expression-system strategy for E. coli-based production of recombinant enzymes and plasmids.

You will design screening cascades and define decision criteria to drive scalable, robust upstream processes. The role requires deep expertise in microbial genetics, molecular biology, and synthetic biology, with experience translating small-scale screening outputs into development-ready