Senior Research Associate / Associate Scientist, Nonclinical

Flagship Pioneering•Cambridge, MA

About The Position

Alltrna is seeking a hands-on scientist to join its Nonclinical team and evaluate engineered tRNA performance across preclinical disease models. The role focuses on selecting, developing, and optimizing assays that measure tRNA activity and efficacy, including cell-based assays in primary cells and hepatocyte models, as well as 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 position offers opportunities to propose ideas, collaborate across the company, and participate in data reviews and decision-making. The successful candidate will take ownership of experiments, work carefully and efficiently, troubleshoot technical challenges, adapt to changing priorities, and maintain scientific rigor. Hiring is at the Senior Research Associate or Associate Scientist level, depending on experience.

Requirements

BS or MS in biology, biochemistry, pharmacology, or a related field.
Minimum of 4+ years of hands-on laboratory experience with a BS, or 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

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 supporting 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), ensuring 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 clearly 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 to share results and communicate progress or issues promptly.