Senior Scientist, Molecular Biology

Flagship Pioneering, Inc.•Cambridge, MA

1d•$126,000 - $181,500

About The Position

Serif Biomedicines, Inc. is seeking 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 ideal 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. The successful candidate will help build and scale platforms for plasmid DNA design, construction, and optimization, focusing on practical, high-throughput workflows and data-driven decision making. This position requires strong technical skills, critical thinking in experimental design, and the ability to thrive in a fast-paced, collaborative environment. The role reports to the Director of Molecular Biology and includes management of one direct report, with close collaboration with other scientists and group leads across the R&D team.

Requirements

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.
Entrepreneurial spirit, strong communication skills, and comfort in working in and contributing to a dynamic and cross-functional team environment.

Nice To Haves

Experience with protein prediction models and ab initio modeling
Experience with affinity and stability characterization of proteins
Experience with automation for arrayed screening and other biochemical assays
Experience with DNA and RNA production, screening, and data analysis workflows
Experience with binder identification and characterization

Responsibilities

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.
Design and build complex DNA libraries, including barcoding strategies, to enable pooled screening and variant tracking.
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 demonstration 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
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.