Senior / Principal Associate Scientist, Advanced Cell Engineering

Company Overview: Strand Therapeutics is a clinical-stage biotechnology company pioneering programmable mRNA therapeutics to unlock the full potential of genetic medicines. Strand is applying its proprietary Signal Stack platform, which integrates EverScript circular RNA, AmpliScript self-replicating RNA, SignalPath targeted delivery, and logic-driven SignalLock genetic circuits to enable precise control of therapeutic activity across tissues and cell types and overcome foundational limitations in targeting, durability, and safety. Strand is advancing a pipeline with an initial focus on oncology and autoimmune disease. Its initial program, STX-001, an intratumorally delivered LNP-encapsulated self-replicating RNA expressing IL-12, has demonstrated preliminary evidence of systemic immune activation and anti-tumor activity in patients with advanced solid tumors who have progressed on prior therapies. Building on this early clinical validation, intravenously delivered STX-003 is designed for tumor-targeted expression and avoidance of off-target expression. STX-003, which is expected to enter the clinic in mid-2026, has the potential to be a major step forward for the fields of genetic medicine and oncology. Strand is also advancing STX-005, an in vivo CAR-T program designed to enable controlled, durable expression and repeat dosing. Founded by MIT synthetic biology pioneers, Strand has raised over $250 million and is headquartered in Boston, MA. Become the next standout single strand! Job Summary: Strand is looking for people who have the enthusiasm and motivation to be a highly contributing member of a small but extremely productive team. This opportunity will offer the employee the ability to work in a matrix-based environment and be a part of the future strategy of the company. We are looking for a Senior / Principal Associate Scientist to join the mRNA Programming department to help drive our efforts utilizing the power of RNA LNP therapeutics in oncology, autoimmune diseases, and beyond. You will be passionate about scientific discovery, undeterred by bold challenges, and enjoy working as a team to develop the next generation of RNA medicines. You should be highly organized, a critical thinker, adaptable to changing priorities, and possess a strong ability to collaborate effectively with teams of diverse backgrounds. Primary Responsibilities: • Design and execution of in vitro immunological and cellular assays to characterize and optimize engineered primary cells. • Develop ex vivo sample processing protocols and execute multiparameter spectral (Cytek Aurora) flow cytometry to analyze drug discovery assay readouts. • Handling primary cells, particularly immune cells including cell isolation, culture and transfection using mRNA encoded therapeutics. • Designing and execution of immune cell assays to assess the efficacy and potential toxicity of key drug candidates. • Employ cell-based and molecular biology assays with standard readout techniques to evaluate quality of research material. • Ensure data collection is captured in electronic laboratory notebooks and databases. • Data collection, data analysis, summarizing results in study reports, and providing regular updates at internal cross-functional meetings. Qualifications: • B.S. or M.S. in Biological Sciences, Bioengineering or related discipline, with at least 2-3+ years of relevant experience in cell biology and/or immunology • 3-5+ years of experience working with flow cytometry analysis, cell culture, in-vitro experimentation with mammalian cell lines in a biotechnology, pharma, CRO or academic setting. • Theoretical and practical understanding of flow cytometry with experience in design and execution of >12 color panels. • Strong laboratory experience