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Research and Development

R&D
Where your curiosity drives the
miracles of
science

Senior Associate Scientist

Waltham, Massachusetts Salary Range   USD 75,000.00 - 108,333.33
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At a glance

Bring your curiosity to a team where deep immunoscience meets cutting-edge innovation. Across oncology, rare diseases, neurology, and vaccines, you’ll work at the intersection of lab science and AI-powered discovery — all while collaborating across boundaries to turn breakthrough ideas into real-world impact. Whether you want to deepen your scientific expertise or grow as a leader, you’ll find the opportunity here.

Job Title: Senior Associate Scientist

  • Location: Waltham, MA

About the Job:

The successful candidate will join a high-performing, collaborative group working on different aspects of mammalian producer cell line (PCL) development our genomic medicine pipeline.  The team’s focus is generation, scale-up and screening of producer cell lines expressing viral vectors for gene therapy, and development of new methods to optimize workflows.  Our mission is to develop robust producer cell lines that meet project milestones and to contribute to cross-functional efforts to optimize our future producer cell line viral vector platform.  Team members have opportunities to work with high-throughput automation systems and to serve as the Cell Line and Vector Development (CLVD) function representative on project teams.

Join the engine of Sanofi’s mission — where deep immunoscience meets bold, AI-powered research. In R&D, you’ll drive breakthroughs that could turn the impossible into possible for millions.

About Sanofi:


We’re an R&D-driven, AI-powered biopharma company committed to improving people’s lives and delivering compelling growth. Our deep understanding of the immune system – and innovative pipeline – enables us to invent medicines and vaccines that treat and protect millions of people around the world. Together, we chase the miracles of science to improve people’s lives.

Main Responsibilities

  • Cell Line Development & Production: Generate and evaluate producer cell lines expressing viral vectors, including all preparatory steps (media preparation, cell maintenance, thaw, and passaging), and produce small-scale cell banks and pre-master cell banks.

  • Automated Systems & Assessments: Operate automated single cell cloning and well-plate imaging systems; perform cell line assessments and associated data management to meet project timelines.

  • Experimental Planning & Execution: Independently plan and execute experiments, manage concurrent work assignments, analyze and interpret results, and propose next steps, consulting with supervisor as needed.

  • Documentation & Communication: Prepare reports, procedures, and presentations for CLVD team members and cross-functional project teams to ensure effective knowledge sharing and project alignment.

  • Laboratory Operations: Contribute to lab organization, reagent tracking, and other operational tasks to maintain an efficient and well-resourced working environment.

  • Compliance & Safety: Ensure all work is conducted in accordance with applicable regulations, SOPs, and policies, maintaining proper records and upholding safe and compliant laboratory practices.

About You

Basic Qualifications:

  • Master’s degree in Biotechnology, Biology, Cell Biology, or related discipline.

  • 1+ year of experience in mammalian cell culture, aseptic laboratory techniques, viral vector production, or related laboratory experience. Academic experience will be considered.

  • Self-motivated with excellent organization and time-management skills.

  • Strong attention to details and communication skills.

Preferred Qualifications:

  • Mammalian cell culture experience in a pharmaceutical or biotechnology or academic setting.

  • Experience driving end-to-end producer cell line development, Hamilton liquid handling automation development and optimization using LLMs, and database architecture to accelerate workflows and enhance data integrity.

  • Experience in mammalian gene expression systems and/or molecular biology techniques.

  • Experience collaborating across multidisciplinary teams to advance processes and translate technical innovation into operational impact.

  • Able to learn quickly and excel in a fast-paced highly cooperative team environment, multitask, adaptability, and positive attitude.

Why Choose Us

  • Bring the miracles of science to life alongside a supportive, future-focused team.

  • Discover endless opportunities to grow your talent and drive your career, whether it’s through a promotion or lateral move, at home or internationally.

  • Enjoy a thoughtful, well-crafted rewards package that recognizes your contribution and amplifies your impact.

  • Take good care of yourself and your family, with a wide range of health and wellbeing benefits including high-quality healthcare, prevention and wellness programs and at least 14 weeks’ gender-neutral parental leave.

  • Be part of a pioneering biopharma company that engages patients early in drug development and uses their insights to design studies that reflect real-world needs.

  • Help improve the lives of millions of people globally by making drug development quicker and more effective.

  • Work at the forefront of drug discovery, harnessing cutting-edge AI, data, and digital platforms to push the boundaries of science.


Sanofi Inc. and its U.S. affiliates are Equal Opportunity and Affirmative Action employers committed to a culturally diverse workforce. All qualified applicants will receive consideration for employment without regard to race; color; creed; religion; national origin; age; ancestry; nationality; marital, domestic partnership or civil union status; sex, gender, gender identity or expression; affectional or sexual orientation; disability; veteran or military status or liability for military status; domestic violence victim status; atypical cellular or blood trait; genetic information (including the refusal to submit to genetic testing) or any other characteristic protected by law.

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All compensation will be determined commensurate with demonstrated experience. Employees may be eligible to participate in Company employee benefit programs, and additional benefits information can be found here.

Pursue Progress. Discover Extraordinary.

Join Sanofi and step into a new era of science - where your growth can be just as transformative as the work we do. We invest in you to reach further, think faster, and do what’s never-been-done-before. You’ll help push boundaries, challenge convention, and build smarter solutions that reach the communities we serve. Ready to chase the miracles of science and improve people’s lives? Let’s Pursue Progress and Discover Extraordinary – together.

At Sanofi, we provide equal opportunities to all regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity, protected veteran status or other characteristics protected by law.

Watch 'One day at Sanofi' and check out our Diversity Equity and Inclusion initiatives at sanofi.com

Final compensation will be determined based on demonstrated experience, skills, location, and other relevant factors. Employees may be eligible to participate in Company employee benefit programs.

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Why work with us

  • Expand your horizons. Grow through curiosity, with support to move, learn, and lead in a culture that champions mentorship, mobility, and bold development.

  • Accelerate results with technology. Harness the power of AI and automation to push scientific boundaries and reimagine what's possible in drug discovery.

  • Impact through inclusive innovation. Help deliver better science and fairer outcomes by driving inclusive research that reaches more people, in more meaningful ways.

  • Turn patient needs into breakthrough science. Drive scientific breakthroughs that start with patient needs – and end in treatments that change lives.

Meet Nils Libert, Associate Scientist

Meet Nils Libert, an Associate Scientist in Belgium, where he plays a key role in advancing groundbreaking research. Learn how his work helps drive innovation, uncover new scientific possibilities, and contribute to life-changing treatments that impact patients around the world.

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EVP & Head of R&D

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