Scientist; I​/II), Protein Production

Mosaic Biosciences is a biotherapeutics drug discovery company that partners with biopharmaceutical companies to discover novel protein and antibody therapeutics. Our experienced and dedicated research teams collaborate with our partners to design, manage, and execute research programs to rapidly advance clinical candidates, starting at any point from early discovery into preclinical development.

Mosaic is seeking a full-time Scientist I or Scientist II to join our Protein Production team in our Boulder, Colorado laboratory. The successful candidate will contribute to the design, execution, and optimization of protein expression and purification strategies while collaborating within cross‑functional project teams. This role requires strong experimental design skills, scientific problem‑solving, and the ability to translate experimental findings into improved workflows that support client discovery programs.

• Design, execute, and optimizerecombinant protein expression strategies in mammalian, bacterial and/or insect systems.
• Develop and refineprotein purification workflows using multi‑step chromatography approaches (e.g., IMAC, SEC, IEX, HIC) and automated systems (e.g., AKTA).
• Analyze experimental results anddesign follow‑up experiments to address technical challenges or improve protein yield, purity, and stability.
• Apply insights fromscientific literature and prior resultsto guide experimental approaches and troubleshoot complex problems.
• Collaborate with cross‑functional teams to supportprotein supply for discovery, characterization, and downstream assay development.
• Ensure experiments are executed with strong scientific rigor,maintaining high‑quality data and reproducible results.
• Communicate scientific findings clearly in team discussions and contribute toproject planning and experimental strategy.
• Maintain accurate and detailed laboratory documentation and support laboratory operations as needed.
• Identify opportunities to improve laboratory workflows, instrumentation practices, and experimental processes to enhance efficiency, reproducibility, and data quality.

• Experience with recombinant protein expression and purification workflows and the ability todesign, execute, and interpret experiments.
• Mammalian expression experience.
• Ability to troubleshoot complex technical challenges andadapt experimental approaches based on scientific findings and literature.
• Strong organizational and communication skills with the ability to collaborate effectively across scientific teams.

• Protein engineering or construct design for recombinant expression.
• Transient transfection / stable cell line generation.
• Experience with automated protein purification systems (e.g., AKTA).
• Experience supporting antibody or biologics discovery programs.

• Scientist I:
  PhD in Biochemistry, Molecular Biology, Chemistry, Chemical Biology, or related field with 0–2 years of relevant industry experience.
• Scientist II:
  PhD in Biochemistry, Molecular Biology, Chemistry, Chemical Biology, or related field with 2+ years of relevant industry experience and demonstrated success advancing protein production workflows.

Full‑time position based in Boulder, CO; in‑person lab work required.

$105,000 - $123,000, depending on experience and position level (Scientist I or Scientist II).

Comprehensive benefits including health and dental insurance, disability and life insurance, 401(k) with company match, and bonus opportunities based on company and individual performance.