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Sr Scientist/ Scientist, Cell Line & Upstream, CMC

 About us 

At Janux, we are developing unique immunotherapies that have the potential to generate tumor-specific immune responses to attack and kill tumors without destroying a patient’s healthy tissue. We believe that combining Janux’s tumor-specific activation with multi-stage anti-tumor signaling will significantly improve safety, expand the therapeutic dosing window, and maximize patient responses. 

As member of the Process Development, CMC group, the Sr Scientist/Scientist will contribute to the development and implementation of mammalian Cell Line Development (CLD) and Upstream Process Development activities to advance Janux TRACTr candidates from research through clinical development towards commercialization. The successful candidate will be responsible for all molecular and cell biology aspects of CLD including vector design and construction, clone screening and characterization. As part of this role, the Sr Scientist/Scientist will lead upstream process development and protein expression to support pre-clinical studies and tech transfer activities to Contract Development and Manufacturing Organizations (CDMO) for clinical manufacturing. 


  • Perform and oversee mammalian cell line development and early-stage upstream process development. 
  • Lead and oversee vector construction, transfection, clone selection and characterization, cell banking and protein expression. 
  • Evaluate and implement practical, and sometimes novel, technologies to improve process productivity and robustness. 
  • Design and perform experiments to identify and establish upstream operating and performance parameters. 
  • Write operational procedures/batch records, process descriptions and technical documents to support process development at CDMOs. 
  • Responsible for operation and preventive maintenance of laboratory equipment. 
  • Maintain detailed records of all experiments performed. 
  • Effectively analyze, organize and communicate experimental results to colleagues and senior leadership. 
  • Train and mentor junior members of the team and collaborates across functional areas. 
  • Travel: up to 25% (domestic and/or international) may be required. 

Required Skills/Qualifications: 

  • Experience with molecular biology methods for mammalian cell engineering. 
  • Experience using multiple transfection methods and selection markers for recombinant protein expression in mammalian cells, preferably CHO. 
  • Extensive knowledge of screening and characterizing clonal cell lines for use in a cGMP environment. 
  • Hands-on experience in cell culture media development and optimization of process parameters using benchtop-scale bioreactors is highly preferred. 
  • Experience with using design of experiments (DOE) software to guide process development. 
  • Experience working with CDMOs. 
  • Working knowledge of downstream processing is a plus. 
  • Strong analytical skills and ability to work in a highly collaborative environment. 
  • Excellent written and oral communication skills. 


  • Ph.D. in Cell and Molecular Biology, Biotechnology, Bioengineering or a related discipline + 3 – 6 years of postdoctoral experience OR an M.S. + 8 – 11 years of industry experience in biologic upstream process development. 


Janux offers a competitive compensation with stock options in addition to a comprehensive benefits package consisting of medical, dental, vision, and supplemental disability insurance. 

Job Type: Full-time 


  • 401K (3% employer matching) 
  • Medical insurance 
  • Dental insurance 
  • Vision insurance 
  • Supplemental disability insurance plans 
  • Flexible schedule 
  • Life insurance 
  • Flexible vacation 
  • Incentive stock option plan 


Monday to Friday On-Site (La Jolla, CA) 

Work authorization: 

  • United States (Required) 

Job Type: Full-time 

COVID-19 Vaccination required

Janux requires all new hires to be fully vaccinated for COVID-19 prior to the first date of employment.  As required by applicable law, Janux will consider requests for Reasonable Accommodations.


Janux Therapeutics, Inc. is an equal opportunity employer that is committed to providing a work environment free of harassment and discrimination based upon a protected category, as well as an environment free from retaliation for protected activity.