Principal Research Associate, Protein Engineering

About the role

Why this role matters.

Our protein engineering campaigns are how Arbor's editing tools get better. More precise, more deliverable, more effective in the cells that matter. This role generates and tests the variants that tell us what's working.

You'll run molecular biology and cell-based screening workflows spanning AAV, IVT mRNA, and sequencing readouts, troubleshoot what doesn't work, and bring back a point of view on what to try next. It's a strong fit for a molecular biologist who can hold several workstreams at once and wants their data to shape where the campaign goes.

What you'll own.

• Execute and optimize molecular biology and cell-based experiments supporting protein engineering campaigns, troubleshooting production, delivery, and assay performance as issues arise.
• Generate and evaluate protein mutants and variants for genome editing applications.
• Run cell-based screening workflows, including transient transfection, nucleofection, and transduction in dividing and non-dividing cell models.
• Design, package, and test AAVs for variant evaluation.
• Synthesize, purify, characterize, and test IVT-generated mRNA.
• Prepare sequencing libraries and support analysis of editing outcomes, variant performance, and assay quality.
• Interpret data, summarize findings, and communicate results clearly to project teams.
• Recommend follow-up experiments, controls, and workflow improvements.
• Keep accurate records and prepare data summaries for cross-functional review.
• Partner with upstream design and downstream testing teams on planning, prioritization, and handoff.

What you've done.

• Bachelor's in biology, biochemistry, molecular biology, or a related field with 5+ years of relevant experience, or a Master's with 3+ years. Industry experience preferred.
• Hands-on molecular biology, cell-based assay, and protein variant evaluation work.
• Supported protein engineering, directed evolution, gene editing, or similar screening campaigns.
• Tissue culture experience, including transient transfection, nucleofection, or transduction.
• Managed multiple experiments or workstreams with general guidance.
• Troubleshoot independently, analyze results, document carefully, and explain findings clearly.
• Preferred: AAV production, IVT mRNA workflows, sequencing library prep, or cell-based editing assays.
• Plus: CRISPR or other gene editing technologies; Illumina sequencing workflows.

What you'll get.

The anticipated base salary range for this role is $95,000 - $110,000. Final offers will depend on experience, skills, and other job-related factors. Every employee is eligible for a bonus and new hire equity.

We pay approximately 90% of medical, dental, and vision premiums and fund the full deductible on our HSA plan. You'll also receive 12 weeks of parental leave at full pay, paid parking or transit, a 401(k) match, and discretionary time off.