Senior Scientist, Protein Engineering in Cambridge

Serif Biomedicines is a privately held, early-stage biotechnology company pioneering Modified DNA as a new class of medicines. Modified DNA brings together the best features of mRNA and gene therapy, while mitigating their limitations, by enabling medicines that are durable, redosable, programmable, and scalable.

The role involves working as a Senior Scientist in Molecular Biology with experience in protein engineering, complex DNA library design, and pooled screening to help build next-generation DNA constructs for programmable medicines. This role is suitable for someone who has worked on CAR/binder design and is comfortable designing and testing large libraries to support discovery and optimization of engineered proteins.

Key responsibilities include:

• Using protein prediction models and ab initio modeling to develop proteins of novel function in silico and drive their selection and validation on wet bench.
• Deep expertise characterizing protein structure and function including affinity, stability, etc.
• Designing and building complex DNA libraries, including barcoding strategies, to enable pooled screening and variant tracking.
• Automation experience for arrayed screening and other biochemical assays.
• Building and scaling high-throughput workflows for DNA and RNA production, screening, and data analysis.
• Demonstrating execution of large-scale library screens to support protein engineering and CAR optimization or binder identification and characterization.
• Protein production and characterization in both bacteria and mammalian cells.
• Contributing to plasmid and construct design for engineered proteins and cell-based systems.
• Owning construct QC, sequence analysis, and tracking of variants, including NGS-based workflows.
• Working with external vendors as needed, balancing internal builds and outsourcing to meet timelines.
• Partnering closely with other teams, including CMC, to provide designs, materials, and timelines.
• Mentoring junior scientists and supporting strong practices in experimental design and data quality.
• Maintaining clear and reproducible records (ELN, sequence tracking, sample management).
• Communicating results clearly to cross-functional teams and leadership.

Who you are:

We encourage all candidates with exemplary experience in related fields to apply.

Technical Expertise:

• BS with 14+ years, MS with 12+ years, or PhD with 5+ years of relevant industry experience in molecular biology, bioengineering, or a related field.
• Deep expertise in protein engineering and CAR.
• Proven track record designing and building complex DNA libraries, including barcoding strategies for pooled screening.
• Strong command of molecular cloning and plasmid design in high-throughput settings.
• Demonstrated ownership of large-scale library screens, from design through execution and data interpretation.
• Expert-level experience with NGS-based library analysis, variant tracking, and sequence QC.
• Ability to operate effectively in cross-functional teams and drive work forward in a fast-paced environment.
• Experience mentoring or managing junior scientists.

Leadership & Collaboration:

• Proven ability to lead complex projects and influence cross-functional teams.
• Strong mentorship skills with commitment to developing others.
• Previous technical or professional management experience.
• Excellent communication skills, with the ability to translate complex ideas across disciplines.

Values and Behaviors:

We are seeking individuals with an entrepreneurial spirit, strong communication skills, and comfort in working in and contributing to a dynamic and cross-functional team environment. At Flagship, we recognise there is no perfect candidate. If you have some of the experience listed above but not all, we encourage you to apply anyway. Experience comes in many forms, skills are transferable, and passion goes a long way. We are dedicated to building diverse and inclusive teams and look forward to learning more about your unique background.

The level of the role will be commensurate with the education and years of experience of the identified candidates. Flagship Pioneering and our ecosystem companies are committed to equal employment opportunity regardless of race, colour, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity or Veteran status.