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Senior Scientist/Cell Biology

Nonclinical R&D | Mountain View, CA | Full Time

Job Description

Job Description: Senior Scientist/Cell Biology

Do you want to grow a company that positively impacts the world? We are seeking a cell biologist with an extensive experience to join our drug discovery team. Responsibilities will include execution and analysis of in vitro cellular assays to support small molecule discovery efforts as well as understanding of mechanisms of action. This individual will work closely with scientists within the group and CROs and present their findings to the department and project teams. The ideal candidate will be self-driven, eager to learn new techniques, highly organized and enjoys working in a creative and dynamic team environment.

twoXAR is an AI-driven drug discovery and development company focused on first-in-class small molecules. The company currently has a development portfolio of over 18 diseases. twoXAR saves years in drug development while generating a 30x hit rate at in vivo efficacy milestones over traditional methods. We have established collaborations with leading biopharmaceutical companies and are now scaling the business and building our internal drug pipeline. twoXAR is venture-backed with financing from SoftBank Ventures and Andreessen Horowitz and has strong ties to Stanford University and MIT. Our management team and advisory board have decades of biopharmaceutical management experience, built software systems used by tens of millions of people, held VP and C-level positions at Fortune 100 companies, and have had previous startups with successful strategic acquisitions.


  • Work with Nonclinical R&D team and CROs to identify, design cellular and functional assays, validate assays, and qualify for screening of small molecules synthesized during hit-lead and lead optimization stages.

  • Contribute to evaluation, optimization and assist in management of external biology CRO resources

  • Be able to troubleshoot, develop technical solutions and optimize experiments at CROs for robust data output

  • Work as part of a cross-functional project team to provide high-impact results.

  • Carefully document research workflows, data and protocols.

  • Capture experimental results in database.

  • Prepare data summaries and reports for sharing with twoXAR Nonclinical R&D and management teams


  • Deep knowledge of molecular biology, cell biology, and the drug discovery process, particularly lead validation through lead optimization stages

  • Strong problem-solving and data analysis skills

  • Ability to handle multiple projects simultaneously and meet aggressive project timelines

  • Excellent interpersonal skills with the ability to engage effectively with various levels of working teams and management.

  • Excellent written and verbal communication skills.

  • Proactive, highly motivated, and comfortable working in a fast-paced, evolving environment 


  • Ph.D. in immunology, molecular or cell biology or related discipline with 3-4 years of industry experience.

  • Hands-on experience in development, optimization and execution of cellular assays applying multiple techniques including primary cell isolation, tissue culture, ELISA, flow cytometry, Western and multiplexing technologies (e.g. Luminex, MesoScale)

  • Demonstrated track record in functional assay development in various therapeutic areas

  • Familiarity with primary cell tissue culture, molecular biology techniques to support mechanism of action studies for drug candidates and target identification

  • Ability to conceive, design and execute hypothesis-testing experiments that directly contribute to project success is essential

  • Proficient in relevant programs for data analysis and visualization, e.g. GraphPad Prism, Microsoft Excel, Microsoft PowerPoint, Microsoft Word

  • Experience working with CROs to manage assay design, execution, and data analysis

twoXAR is proud to be an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, gender, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status.