In Vitro Biology Group Leader

Company: JLSa2
Location: South San Francisco
Posted on: March 7, 2026

Job Description:

JLSa2, founded in 2024, is a well-resourced, seed-stage venture backed company located in South San Francisco currently developing a robust pipeline of novel protein-drug conjugate therapies to better address human metabolic diseases and other non-oncology related diseases. We are seeking an experienced and highly motivated In Vitro Biology Group Leader to lead a team responsible for the design, development, validation, and execution of in vitro assays to support drug discovery and translational research programs. This role will provide scientific leadership, technical expertise, and strategic direction in assay development across multiple therapeutic areas. The successful candidate will work cross-functionally with biology, chemistry, pharmacology, and translational teams to drive target validation, lead optimization, and candidate selection. Key Responsibilities Scientific Leadership Lead the design, optimization, and validation of robust in vitro assays to support target discovery, hit identification, and lead optimization. Provide strategic input into quantitative assay development and screening strategies. Oversee assay transfer, automation, and scale-up for project screening needs. Ensure assay reproducibility, robustness, and data integrity. Team Management Recruit, mentor, and develop a team of scientists and research associates. Foster a collaborative, innovative, and high-performance research environment. Set clear performance goals and provide ongoing feedback and career development support. Experimental Oversight Ensure proper statistical analysis and interpretation of experimental data. Guide troubleshooting and continuous improvement of assay performance. Supervise development of: Reporter gene assays Signal transduction assays Proliferation and cytotoxicity assays CRISPR/Cas9-based cell-line development for specialized functional assays 2D and familiarity with 3D cell culture models (including spheroids and organoids) Cross-Functional Collaboration Partner with chemistry and protein engineering to contribute to SAR strategy using biological data. Collaborate with-in vivo teams to correlate in vitro and in vivo findings. Support assay development for translational biology applications, particularly biomarker applications. Contribute to project teams and present data to senior leadership. Support external collaborations and CRO oversight when needed. Compliance & Quality Ensure laboratory practices comply with Good Research Practices, internal SOPs, and regulatory standards. Maintain accurate documentation and electronic data management systems. Qualifications Education & Experience PhD in Cell Biology, Molecular Biology, Pharmacology, Biochemistry, or related field with 8 years of relevant industry experience OR MS with 12 years of relevant industry experience Demonstrated leadership experience managing scientific teams in quantitative biology. Technical Expertise Strong understanding of pharmacology principles (EC50, IC50, dose-response modeling). Strong background in mammalian cell culture and assay development. Hands on experience with automation instrumentation such as Bravo, Kingfisher, Envision, data processing software such as Graphpad Prism, and DNA analysis software. Proficiency in assay technologies such as: Luminescence/fluorescence-based assays ELISA, Western blotting Flow cytometry qPCR and gene expression analysis Familiarity with automation platforms and workflows. Experience with high-content imaging and analysis platforms. Desired Skills Experience working in matrixed drug discovery teams. Experience in one or more therapeutic areas (e.g., metabolic disease, obesity, immunology). Knowledge of translational biomarkers. Strong publication and/or patent record (if applicable). Key Competencies Strategic thinking and scientific rigor Strong leadership and people management skills Excellent communication and presentation skills Data-driven decision making Ability to manage multiple programs simultaneously Reporting Structure Reports to: VP/SVP of Biology Direct Reports: Scientists and Research Associates Work Environment Laboratory-based position with office responsibilities May require occasional travel Salary Range: $190,000 to $225,000 (Compensation will be commensurate with experience/expertise/level and could fall outside of the stated range)

Keywords: JLSa2, Fremont , In Vitro Biology Group Leader, Science, Research & Development , South San Francisco, California