Principal Scientist, Molecular Biology

CSL's organization is accelerating innovation to deliver greater impact for patients. With a project-led structure and a focus on collaboration, we’re building a future-ready team that thrives in dynamic biotech ecosystems. Joining CSL now means being part of an agile team committed to developing therapies that make a meaningful difference worldwide. Could you be our next Principal Scientist, Molecular Biology? The job is in our Waltham MA. This is an onsite position five days a week. You will report to the Director, Molecular Biology. You will provide expertise in Molecular Biology to support drug discovery efforts leveraging novel modalities across CSL R&D and external collaborations. This role requires deep expertise across multiple modalities, experience working with academic and industry partners, and the ability to drive innovation and advance drug candidates from early discovery through clinical development. You will be a highly creative and rigorous scientist with the ability to solve complex scientific problems through innovative, non-obvious approaches. In alignment with CSL’s Novel Modalities strategy, the role will contribute to advancing gene expression modulation approaches and next-generation genetic medicines, with a focus on technology development, translational applicability, and pipeline progression. 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 (e.g., RNA-, DNA-, and gene editing–based approaches) to drive therapeutic design, optimization, and mechanistic understanding. Develop and implement novel approaches to address complex scientific challenges and critical program needs. Establish and scale new technologies and workflows efficiently to accelerate discovery and decision-making. Evaluate and incorporate impactful technologies (e.g., AI-enabled design, multi-omics, advanced sequencing) to support internal and external programs. 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 & Qualifications 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. Strong track record of scientific achievement in a relevant life sciences field, ideally including high-impact publications and/or a strong patent record. Recognized as an innovative and scientifically rigorous researcher with deep subject matter expertise. Experience working in cross-functional and multidisciplinary environments. Expertise in several of the following areas is required: 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) and multi-omics Computational or AI-enabled molecular design The expected base salary range for this position at hiring is $158,000-180,000. Please note this salary range reflects the minimum and maximum base pay that CSL expects to pay for this position at the time of this posting in MA. Individual base salary for a successful candidate is determined by qualifications, skill level, experience, competencies and other relevant factors. In addition to base salary, total compensation for this role may also include incentive compensation and equity. About CSL Behring CSL Behring is a global biotherapeutics leader driven by our promise to save lives. Focused on serving patients’ needs by using the latest technologies, we discover, develop and deliver innovative therapies for people living with conditions in the immunology, hematology, cardiovascular and metabolic, respiratory, and transplant therapeutic areas. We use three strategic scientific platforms of plasma fractionation, recombinant protein technology, and cell and gene therapy to support continued innovation and continually refine ways in which products can address unmet medical needs and help patients lead full lives. CSL Behring operates one of the world’s largest plasma collection networks, CSL Plasma. Our parent company, CSL, headquartered in Melbourne, Australia, employs 32,000 people, and delivers its lifesaving therapies to people in more than 100 countries. To learn more about CSL, CSL Behring, CSL Seqirus and CSL Vifor visit and CSL Plasma at Our Benefits For more information on CSL benefits visit How CSL Supports Your Well-being | CSL. 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