Senior Research Associate / Associate Scientist, Nonclinical

Flagship Pioneering, Inc.•Cambridge, MA

3d•$81,000 - $126,500

About The Position

Alltrna is hiring a hands-on scientist to join its Nonclinical team and test engineered tRNA performance across preclinical disease models. The role suits a detail-oriented, intellectually curious cell and molecular biologist who works well in a collaborative, fast-paced small-company environment. The successful candidate will select, develop, and optimize assays measuring tRNA activity and efficacy, including cell-based assays in primary cells and hepatocyte models and RNA and protein readouts supporting in vivo studies. The scientist will design, execute, and analyze experiments that support platform expansion and advance early-stage programs toward clinical development. The role offers opportunities to propose new ideas, collaborate across the company, and participate in data reviews and decision-making. Hiring level—Senior Research Associate or Associate Scientist—depends on experience. Alltrna is a clinical-stage biotechnology company developing tRNA medicines for diseases caused by shared mutations. Its initial programs aim to restore full-length protein production in diseases caused by premature termination codons. The company was founded in 2018 by Flagship Pioneering and has developed an integrated platform for designing, optimizing, and delivering engineered tRNA therapeutics.

Requirements

BS or MS in biology, biochemistry, pharmacology, or a related field.
At least 4 years of hands-on laboratory experience with a BS, or at least 2 years with an MS, in academia, biotechnology, or the pharmaceutical industry; more experience is required at the Associate Scientist level.
Strong experience in mammalian cell culture, including primary cells and cell lines.
Experience with cell line characterization and development, including growth curves, kill curves, clonal expansion, and mycoplasma testing.
Hands-on experience with DNA/RNA delivery methods such as transfection, lentiviral or AAV transduction, electroporation, or LNP-based delivery.
Experience with PCR, qPCR/RT-qPCR, and molecular cloning.
Experience with Western blot/Jess.
Experience with immunocytochemistry (ICC), immunohistochemistry (IHC), and immunofluorescence (IF).
Experience with luciferase/bioluminescence assays and flow cytometry.
Experience designing and optimizing cell-based assays for drug discovery.
Ability to analyze data using appropriate statistical methods and clearly communicate experimental results.
Strong attention to detail and ability to follow established procedures accurately.
Ability to manage multiple tasks, adapt to changing priorities, and work effectively in a fast-paced biotech environment.
Strong communication, organization, and teamwork skills.

Nice To Haves

Stem cell experience.
Experience working with RNA therapeutics, including mRNA, siRNA, or antisense oligonucleotides.
Experience culturing primary human hepatocytes, induced pluripotent stem cells (iPSCs), or iPSC-derived hepatocyte-like cells.
Experience with high-content imaging, IncuCyte, or confocal microscopy.
Experience with genetic manipulation using CRISPR or other genome-editing approaches.
Experience developing disease-specific cellular assays.
Experience with ligand-binding assays and multiplex immunoassay platforms such as MSD or Luminex for cytokine, immunogenicity, or biomarker analysis.

Responsibilities

Design, optimize, qualify, validate, and implement cell-based assays for early-stage discovery, selection of new indications, and advancement of lead candidates into IND-enabling studies.
Execute in vitro assays and process in vitro and in vivo samples for nonclinical studies, following approved protocols and SOPs.
Conduct biochemical assays supporting development of clinical and nonclinical biomarkers.
Document experiments accurately and promptly in the electronic laboratory notebook (ELN), maintaining data integrity, traceability, and complete records.
Perform mammalian cell culture, cell line characterization, and cell line development, including DNA/RNA delivery by transfection, transduction, electroporation, or LNP-based methods.
Perform molecular and cellular assays, including PCR/qPCR, Western blot/Jess, immunostaining, luciferase/bioluminescence assays, and flow cytometry.
Analyze, interpret, and present experimental results to the Nonclinical and Research Leadership Teams.
Contribute to SOP development and manage reagents and inventory to support consistent, reproducible experiments.
Manage multiple studies in parallel, adapt to shifting priorities, and meet study timelines.
Collaborate with team members and cross-functional partners, sharing results and promptly communicating progress or issues.