Serif Biomedicines | Cambridge, MA Senior Scientist, Molecular Biology

Serif Biomedicines, Inc. is a privately held, early‑stage biotechnology company developing a novel approach to gene therapy that can address currently untreatable diseases.

We are looking for a Senior Scientist, 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 a good fit 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.

You will help build and scale platforms for plasmid DNA design, construction and optimization, with a focus on practical, high‑throughput workflows and data‑driven decision making. We are looking for someone who brings strong technical skills, thinks critically about experimental design and is comfortable working in a fast‑paced, collaborative environment. This role reports to the Director of Molecular Biology and includes management of one direct report.

You will work closely with other scientists and group leads across the R&D team.

• Use protein prediction models and ab initio modeling to develop proteins of novel function in silico and drive their selection and validation on wet bench
• Demonstrate deep expertise in characterizing protein structure and function including affinity, stability, etc.
• Design and build complex DNA libraries, including barcoding strategies
  , to enable pooled screening and variant tracking.
• Have automation experience for arrayed screening and other biochemical assays.
• Help build and scale high‑throughput workflows for DNA and RNA production, screening, and data analysis
  .
• Track record of demonstrating execution of large‑scale library screens to support protein engineering and CAR optimization or binder identification and characterization.
• Produce proteins and characterize them in both bacteria and mammalian cells.
• Contribute to plasmid and construct design for engineered proteins and cell‑based systems.
• Own construct QC, sequence analysis and tracking of variants, including NGS‑based workflows.
• Work with external vendors as needed, balancing internal builds and outsourcing to meet timelines.
• Partner closely with other teams, including CMC, to provide designs, materials and timelines.
• Mentor junior scientists and support strong practices in experimental design and data quality.
• Maintain clear and reproducible records (ELN, sequence tracking, sample management).
• Communicate results clearly to cross‑functional teams and leadership.

• 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.
• 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.

The salary range for this role is $126,000 – $181,500. Compensation will depend on a candidate’s qualifications, skills, competencies and experience. Serif Biomedicines offers healthcare coverage, an annual incentive program, retirement benefits and a broad range of other benefits.

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