Principal Scientist, Molecular Biology

CSL’s organization is accelerating innovation to deliver greater impact for patients. This onsite Principal Scientist, Molecular Biology position is located in Waltham, MA and reports to the Director, Molecular Biology. The role requires deep expertise across multiple modalities, experience with academic and industry partners, and the ability to drive innovation and advance drug candidates from early discovery through clinical development.

• Leadership and Strategy – Contribute to scientific direction supporting CSL’s novel modalities portfolio and pipeline; participate in external due diligence assessing modality suitability, technical feasibility, and risk; identify scientific and technology gaps and propose innovative approaches to enable program advancement.
• Research and Development – Design, execute, and interpret complex experiments with high scientific rigor, creativity, and efficiency; advance programs from concept through preclinical development toward clinical candidates; apply expertise across molecular modalities (RNA, DNA, gene‑editing, etc.) to drive therapeutic design, optimization, and mechanistic understanding; develop novel approaches to address complex scientific challenges; establish and scale new technologies and workflows efficiently; evaluate and incorporate impactful technologies such as AI‑enabled design, multi‑omics, and advanced sequencing.
• Scientific Oversight – Serve as a subject‑matter expert in Molecular Biology and genetic medicines; provide scientific guidance and mentorship to team members and collaborators; ensure robust experimental design, data quality, and interpretation aligned with appropriate scientific standards; communicate findings, risks, and recommendations clearly to diverse audiences, including senior leadership; contribute to intellectual property activities through technical input and scientific insight.

• Education:
  
  PhD or MSc with 8+ years of relevant experience in Molecular Biology or a related discipline in industry and/or academia, with demonstrated progression in scientific responsibility.
• Experience:
  
  Strong track record of scientific achievement in a relevant life sciences field, ideally including high‑impact publications and/or a strong patent record.
• Skills:
  
  Recognized as an innovative and scientifically rigorous researcher with deep subject‑matter expertise; experience working in cross‑functional and multidisciplinary environments.
• Technical Expertise:
  Proficiency in at least one of the following areas: RNA therapeutics (e.g., siRNA, mRNA, circRNA, saRNA), gene editing and/or gene therapy, gene‑expression regulation and modulation, next‑generation sequencing (short‑read and long‑read) with multi‑omics, computational or AI‑enabled molecular design.

The expected base salary range for this position at hiring is $158,000‑180,000. Individual base salary will be determined by qualifications, skill level, experience, competencies, and other relevant factors. Total compensation may also include incentive compensation and equity.

CSL is an Equal Opportunity Employer. If you are an individual with a disability and need a reasonable accommodation for any part of the application process, please visit  CSL Global Privacy Notice for Job Applicants and Candidates.