Company Description 

FL121 is a privately held biotechnology company engineering nature to build next generation therapeutics. By harnessing naturally occurring chemistry and pairing it with sophisticated high-throughput screening technology, we will unlock the future of de novo drug design via curated data creation and model training.  

Role Overview 

We are building a therapeutic discovery platform centered on biosynthetically-derived chemistry and advanced analytical readouts. This role will provide direct experimental support to the platform’s Build arm: executing cloning, expression, and purification workflows with a high degree of independence and rigor. The Sr. RA will be a hands-on contributor to day-to-day bench operations and will help maintain the throughput and data quality needed to drive rapid, data-grounded decisions. 

Key Responsibilities 

• Execute molecular cloning workflows end-to-end using modern assembly methods (Gibson, T2S/Golden Gate, and related approaches); maintain accurate plasmid maps, sequence records, and construct libraries. 

• Express and purify recombinant proteins in bacterial systems; independently troubleshoot yield, solubility, and purity issues across the full workflow from culture through final polishing steps. 

• Maintain rigorous records of experimental conditions, reagent lots, and QC data; contribute to reproducible, well-documented protocols and sample tracking practices that support downstream analytical and screening steps. 

• Partner with senior scientists and cross-functional teams to deliver high-quality material inputs that enable platform proof-of-concept experiments; communicate results and blockers clearly and proactively. 

Required Skills and Experience 

• Demonstrated proficiency in modern DNA assembly methods (Gibson Assembly, Type IIS/Golden Gate, and related scarless cloning strategies); able to take a construct from design to sequence-verified clone independently. 

• Hands-on experience with recombinant protein expression (E. coli required; additional systems a plus) and purification by affinity chromatography and related downstream steps; able to assess purity and integrity via analytical methods. 

• Familiarity with standard analytical tools (chromatography, gel electrophoresis, UV absorbance) and biochemical assays (ELISA, BLI) for protein and DNA characterization 

• Track record of executing multi-step molecular biology workflows end-to-end with minimal supervision; strong attention to detail in protocol execution and data recording. 

• Senior Research Associate: Typically requires a BS degree in a relevant scientific discipline with 5+ years of industry experience; or a Master’s degree in a relevant scientific discipline with 3+ years of experience. Academic experience including co-ops and internships counts toward degree requirements and not work experience. 

Preferred Experience 

• Experience supporting or interfacing with mass spectrometry-based readouts. 

• Experience with laboratory automation platforms, LIMS/sample tracking systems, or basic scripting (Python/R) for data organization and analysis. 

What it Takes to Succeed in This Role 

• Comfort in ambiguity; can move between strategy and execution. 

• Creative and rigorous in experimental design, documentation, and data interpretation. 

• Collaborative communicator; gives/receives feedback effectively. 
• Grit and agility in fast-moving environments. 

Values and Behaviors 

We are seeking individuals with an entrepreneurial spirit, strong communication skills, and comfort working in and contributing to a dynamic and cross-functional team environment. The level of the role will be commensurate with the education and years of experience of the identified candidate. 

At Flagship, we recognize there is no perfect candidate. If you have some of the experience listed above but not all, please 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. 

Recruitment & Staffing Agencies: Flagship Pioneering and its affiliated Flagship Lab companies (collectively, “FSP”) do not accept unsolicited resumes from any source other than candidates. The submission of unsolicited resumes by recruitment or staffing agencies to FSP or its employees is strictly prohibited unless contacted directly by Flagship Pioneering’s internal Talent Acquisition team. Any resume submitted by an agency in the absence of a signed agreement will automatically become the property of FSP, and FSP will not owe any referral or other fees with respect thereto. 

The salary range for this role is $81,000 - $107,250. Compensation for the role will depend on a number of factors, including a candidate’s qualifications, skills, competencies, and experience. FL121 currently offers healthcare coverage, annual incentive program, retirement benefits and a broad range of other benefits. Compensation and benefits information is based on FL121's good faith estimate as of the date of publication and may be modified in the future.