Senior / Principal Associate Scientist, Advanced Cell Engineering

Strand Therapeutics; Boston (MA); On-site; USD 84,000 - 112,000; Full time

Benefits offered by this job

Equity incentives

Bonus eligible

Open PTO

Health benefits

Onsite lunch

Job summary

Strand Therapeutics is seeking a Senior / Principal Associate Scientist in the mRNA Programming department to advance RNA LNP oncology therapies. You will design and execute immunological assays, work with primary cells, and analyze data to support development of next-generation RNA medicines.

A collaborative, fast-paced environment offers equity incentives and strong benefits. Ideal candidates have 2–3+ years in cell biology/immunology, extensive flow cytometry experience, and expertise in mRNA

Qualifications

• BS/MS in Biological Sciences, Bioengineering, or related field with 2-3+ years of relevant experience.
• 3-5+ years of flow cytometry, cell culture, and in vitro assays with mammalian cells in biotech, pharma, CRO, or academic settings.
• Experience designing >12 color flow cytometry panels and analyzing diverse sample types (blood, PBMC, cell lines).
• Experience with mRNA transfection using LNPs and/or electroporation is highly desired.
• Proficiency in SOPs, record keeping, and cross-functional communication.

Responsibilities

• Design and execute in vitro immunological and cellular assays to characterize engineered primary cells.
• Develop ex vivo sample processing and perform multiparameter flow cytometry readouts.
• Handle primary immune cells, including isolation, culture, and transfection with RNA therapeutics.
• Design and execute immune cell assays to assess efficacy and potential toxicity of drug candidates.
• Use standard molecular biology and cell-based assays, ensure data captured in ELN/LIMS.

Skills

Flow cytometry

Cell culture

mRNA transfection

Data analysis

Education

B.S./M.S. in Biological Sciences or related

Tools

FlowJo

GraphPad Prism

Excel

PowerPoint

ELN/LIMS

Job description

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, anin vivoCAR-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 and expertise working with a variety of sample types including whole blood, PBMC, cell lines and single-cell suspensions from tissue samples.
• Experience with mammalian cell manipulation using mRNA transfection using LNPs and/or electroporation highly desired.
• Experience performing cell-based assays including in vitro/ex vivo cytotoxicity assays, proliferation, ELISA will be preferred.
• Ability to independently write, edit, and follow standard operating procedures, make careful detailed observations, maintain clear and complete records of lab work.
• Ability to clearly communicate results and findings in cross-functional team meetings.
• Proficient in Excel, PowerPoint, Graphpad Prism, FlowJo and ELN/LIMS for data entry, analysis, and presentation.
• High level of integrity and adherence to strict compliance standards.

Preferred Qualifications:

• Experience with mammalian cell manipulation using mRNA transfection and/or electroporation.
• Experience performing cell-based assays including in vitro/ex vivo cytotoxicity assays, proliferation and ELISA/MSD.
• Plasmid cloning, RNA handling, IVT, transfection and transduction of primary cells.
• Experience with gene/base editors preferred.
• Familiarity with lab automation systems such a Hamilton liquid handlers, AssistPlus.

Strand offers a fast-paced, entrepreneurial, team-focused small company environment. We also offer a top-notch benefits package (health, dental, life, open PTO, onsite lunch catering, commuter support and more) and work/life flexibility and integration. Being part of the Strand team allows you to become part of a small team that supports professional development while working together to meet Strand’s goals.

Strand Therapeutics is an equal opportunity employer. We do not discriminate on the basis of race, color, gender, gender identity, sexual orientation, age, religion, national or ethnic origin, disability, protected veteran status or any other basis protected by applicable law. Strand does not accept unsolicited resumes from any source other than directly from candidates.

Job Type: Full-time

Salary: $84,000 - $112,000 annually plus bonus and equity incentives

Pay Transparency Base Salary Range

$84,000 - $112,000 USD