Senior Scientist/Principal Scientist, Protein Sciences: Analytical & Biophysical Characterizations

Work Location: On-site role at our Corporate Headquarters (South San Francisco)

Position Summary: Soleil is seeking an expert, hands‑on scientist to lead our analytical and biophysical characterization efforts within the Protein Sciences group of the Technology team. In this role, you will design, develop, validate, and execute comprehensive developability assessments and analytical characterizations for our biologics portfolio (antibodies, multi‑specifics, fusion proteins). You will be the go‑to expert for complex analytical challenges, drive technical strategy across programs, and work collaboratively with research and development teams to generate critical data that inform candidate selection and progression. This is a highly technical, hands‑on position where you will spend time at the bench while contributing strategic leadership on analytical and developability matters.

Responsibilities: Analytical Design & Execution: Design, develop, validate, and execute analytical and biophysical methods (with emphasis on LC-MS, chromatography, thermal/structural assays, and immunogenicity assessments) for diverse protein and antibody formats Establish robust, fit-for-purpose assays that characterize therapeutic biologics throughout the preclinical pipeline Execute experiments with precision, conduct detailed observations, analyze and interpret data rigorously, and deliver results in a timely, concise manner to program teams Developability & Characterization Strategy: Prepare and lead comprehensive developability assessment packages for biologic candidates, evaluating stability, solubility, aggregation, post‑translational modifications, manufacturability, immunogenicity potential, and key risk factors Serve as technical lead for due diligence and business development contexts: evaluate external analytical data, review technical packages, identify risk, and advise senior decision‑makers on analytical feasibility and candidacy Define analytical strategy across the portfolio in collaboration with research, CMC, and program teams; ensure alignment with formulation and process development Troubleshooting & Technical Leadership: Serve as SME for complex analytical and characterization challenges; provide expert guidance to cross‑functional teams on technical issues and method refinements Evaluate emerging analytical technologies for feasibility and performance; guide adoption to enhance throughput, sensitivity, and risk mitigation Mentor junior scientists and collaborate with peers on scientific approaches and best practices Lead a focused analytical team (1 direct report) while managing CRO partnerships for specialized assay work, validation, and tech transfer. Play a key analytical role in drug candidate selection decisions across the portfolio; advise senior leadership on analytical feasibility and developability risk Documentation & Communication: Prepare precise technical summaries, protocols, analytical packages, and maintain rigorous documentation standards suitable for regulatory submissions and internal reporting Contribute to program team discussions as a functional technical lead, effectively communicate across line‑functions This is a full‑time, lab‑based position combining hands‑on technical execution with leadership and strategic responsibilities.

Education & Experience: Ph. D. or equivalent in a related discipline (e.g. molecular biology, biochemistry, biophysics, analytical chemistry) with 5+ years' experience in protein and antibody characterization and developability in an industry setting, preferably startup or biotechnology companies Technical Expertise: Expert in biophysical and analytical techniques including but not limited to HPLC, CE, SPR, DSF, DSC, SEC‑MALS, LC‑MS, and immunogenicity assays Solid, hands‑on understanding of protein analytical principles, methodologies, and PTMs characterization Extensive, hands‑on experience in developability studies for antibody therapeutics, including monoclonal, bispecific, and multi‑specific antibodies, fusion proteins, and antibody‑drug conjugates Deep understanding of attributes of protein therapeutic drug candidates and biologics drug discovery process (hit‑to‑lead, lead optimization, candidate selection) Experience with protein purification, membrane proteins, and/or multi‑specific antibody formats is highly desired Demonstrated excellence at troubleshooting complex analytical and characterization challenges and explaining technical approaches to cross‑functional audiences Strong attention to detail in experimental design and execution; capable of running multiple experiments in parallel without compromising quality or rigor Excellent oral presentation and written communication skills, with ability to synthesize complex data into clear summaries for technical and non‑technical stakeholders Strong collaborative and mentoring skills; able to work effectively across functional groups and help junior scientists develop Flexible, adaptable, and quick to learn new techniques and technologies; thrives in fast‑paced, dynamic environments Familiarity with CMC development process; prior experience with IND filing is highly desired Prior experience with managing direct report(s) is preferred

Company Overview: TCG Labs‑Soleil, established in partnership with The Column Group, a science‑focused venture capital firm, is pioneering a novel ‘venture capital‑biotech’ model. Our core mission is to efficiently translate scientific insights into therapeutic solutions for patients facing serious diseases. This model supports scientific entrepreneurs from the initial idea to clinical proof of concept (PoC) by combining a dedicated fund (TCG Labs) with our independent, evergreen R&D center led by a top‑tier scientific team (Soleil). Together, we create an integrated ecosystem that fosters the development of single‑asset portfolio companies, strategically poised for transacting after clinical PoC.TCG Labs‑Soleil is an Equal Opportunity Employer. We do not discriminate against qualified applicants based upon any protected group status, including but not limited to race, religion, color, creed, sex (including breastfeeding and related conditions), gender identity/gender expression, pregnancy (including childbirth and related conditions), national origin, ancestry, age, marital status, military or veteran status, sexual orientation, genetic information, physical or mental disability or medical condition as defined by applicable equal opportunity laws. Any request for accommodation can be directed to contact@tcglsoleil.com. Benefits and CompensationTCG Labs‑Soleil provides a competitive benefits package that includes access to Medical, Dental, and Vision Insurance, Life Insurance, Short and Long Term Disability, Health Savings Account (HSA), Flexible Spending Accounts (FSA), 401k plan and PTO.The anticipated salary range for fully qualified candidates applying for this role will be$140,000 - $210,000annually (not including discretionary bonus, equity, and benefits). The final salary offered will be dependent on several factors that include but are not limited to relevant previous experience including duration and type of experience within the industry, education, and internal equity, as well as alignment with market data, including potential adjustments for geographic location. TCG Labs‑Soleil does not accept unsolicited agency resumes and will not pay fees to any third‑party agency or firm that doesn’t have a signed agreement with TCG Labs‑Soleil. Please do not send agency CVs/resumes through TCG Labs‑Soleil website or TCG Labs‑Soleil Employees. Inquiries must be sent to contact@tcglsoleil.com with the Subject Heading: Staffing Agency Request.