Senior Scientist I

Job Description Position Summary We are seeking a highly motivated Senior Scientist to join our Protein Expression and Purification group at our South San Francisco site. The successful candidate will play a crucial role in the discovery of novel therapeutics through design and execution of biologics and protein expression activities with a primary focus on mammalian systems. The successful candidate will bring deep expertise in recombinant biologics production including monoclonal antibodies, multispecific scaffold and novel protein modalities particularly in CHO and HEK293 systems and will contribute to advancing discovery-stage biologics programs. Key Responsibilities Design, execute, and optimize recombinant protein expression workflows in mammalian systems (e.g., CHO, HEK293), including transient and stable expression. Develop and implement strategies to improve protein yield, quality, and scalability for biologics production. Represent the Protein Design and Production group in project team meetings and propose the best path forward, contribute to decision‑making process and coordinate efforts with stakeholders. Contribute to DNA construct design, including vector design, cloning strategies, and sequence optimization. Work with CROs to coordinate outsourcing production activities. Collaborate with cross‑functional teams (protein purification, analytics, discovery teams) to deliver high‑quality biologics. Evaluate and introduce new technologies to enhance efficiency of protein expression platforms. Troubleshoot complex expression challenges and propose innovative solutions. Maintain accurate documentation of experiments and communicate results effectively to stakeholders. Ensure compliance with safety protocols and maintain a clean and organized laboratory environment. Collaborate effectively with a group of scientists and demonstrate inclusive behaviors to drive our core mission. Qualifications Desired Experience and Skills Extensive hands‑on experience in recombinant protein and biologics expression in mammalian systems. Strong knowledge of cell culture, transfection, process development and cell line development strategies. Solid background in molecular biology, including construct design, cloning, and plasmid engineering. Experience working with antibody and complex biologics, bispecifics, fusion proteins. Commitment to maintaining accurate and timely records in Electronic Laboratory Notebooks (ELN) and databases. Strong problem‑solving skills and ability to work in a fast‑paced environment. Excellent communication and collaboration skills. Preferred Skills Experience with protein production in bioreactors is a plus but not required. Knowledge of protein purification and characterization techniques. Experience with bioinformatics tools for sequence analysis and construct design. Education Requirements PhD in Molecular Biology, Cell Biology, Biochemistry, or a related discipline with 3+ years of relevant experience (industry preferred); or MS with 4+ years or BS with 7+ years of significant industry experience. Required Skills Cell Cultures, Cross‑Functional Collaboration, Detail‑Oriented, High‑Throughput Screening, Laboratory Documentation, Mammalian Cell Culture, Molecular Biology Techniques, Primary Cell Culture, Protein Expression, Protein Purifications, Recombinant Protein Expression, Results‑Oriented, Safety Protocols, Safety Standards. Benefits and Compensation The salary range for this role is $131,400.00 – $206,800.00. The successful candidate will be eligible for an annual bonus and long‑term incentive, if applicable. We offer a comprehensive package of benefits that includes medical, dental, vision, insurance (for employee and family), retirement benefits including 401(k), paid holidays, vacation, and compassionate and sick days. More information about benefits is available at Legal and Miscellaneous As an Equal Employment Opportunity Employer, we provide equal opportunities to all employees and applicants for employment and prohibit discrimination on the basis of race, color, age, religion, sex, sexual orientation, gender identity, national origin, protected veteran status, disability status, or other applicable legally protected characteristics. As a federal contractor, we comply with all affirmative action requirements for protected veterans and individuals with disabilities. For more information about personal rights under the U.S. Equal Opportunity Employment laws, visit the EEOC website. San Francisco Residents Only: We will consider qualified applicants with arrest and conviction records for employment in compliance with the San Francisco Fair Chance Ordinance. Los Angeles Residents Only: We will consider for employment all qualified applicants, including those with criminal histories, in a manner consistent with the requirements of applicable state and local laws, including the City of Los Angeles' Fair Chance Initiative for Hiring Ordinance. Requisition ID: R405544 Employee Status: Regular Relocation: Domestic Visa Sponsorship: Yes Travel Requirements: 10% Flexible Work Arrangements: Not Applicable Shift: 1st – Day Valid Driving License: No Hazardous Materials: N/A #J-18808-Ljbffr Merck & Co.