Research Associate I/II: Upstream Process Development

Process Sciences South San Francisco, California


Research Associate I/II:

Upstream Process Development

About CytomX Therapeutics:

CytomX Therapeutics, Inc. is committed to changing the treatment of cancer with our novel Probody™ therapeutic platform. Our commitment to transforming lives with safer, more effective therapies is driven by our curiosity and passion for innovation and our belief that by acting with integrity in an honest, respectful, ethical manner, we have the power to change lives. Our workplace embodies collaboration, open communication, celebrating our successes and holding each other to the highest possible standards. CytomX has a broad pipeline comprised of 4 clinical-stage programs and others in development and is located in South San Francisco, California, the birthplace of biotechnology. Learn more at


Location: South San Francisco, California


Reporting Relationship: Associate Director or Scientist 2


The Opportunity:

Professional Responsibilities:

  • Operation, harvest, and cleaning of stirred-tank bioreactors (AMBR15, 2-20L glass vessels, 50 L SUB, fed-batch)
  • Media and reagent preparation to support upstream activities
  • Execute and evaluate of fed-batch cell culture studies in shake flasks and micro-bioreactors
  • Titer analysis using ForteBio Octet, occasional performance of other assays as needed
  • Experimental design and analysis, commensurate with experience
  • Authorship or contribution to SOPs and development reports
  • Support of GMP mfg; may include BPR review and PIP duties
  • Participation in group and department meetings & coordination with Purification and Analytics
  • Requires sharing in weekend sampling duties, typically 2-3 h, once or twice monthly
  • May require occasional lifting; up to 50 pounds



  • For RAI: BS in Biochemistry, Molecular Biology, or Cell Biology with 0-2 yrs. related experience

OR Associate’s Degree with 4+ years

  • For RAII: BS in Biochemistry, Molecular Biology, or Cell Biology with 2-5 yrs. related experience OR an MS/ChemE/MBS/PSM degree related to industrial cell culture and 0-3 yrs. experience


Professional Requirements:

  • Candidates with experience in a cell culture process development setting, including operation of stirred-tank bioreactors and associated instruments are strongly preferred. Advanced troubleshooting and data analysis skills are highly desired.
  • Knowledge of bioengineering concepts (e.g. PID control, kLa, scaleup/scaledown etc.),
  • Familiarity with using and programming SCADA software (BioXpert, Lucullus, MFCS etc.). Additional experience with automation or microbioreactor systems (esp Ambr15) is preferred.
  • Familiarity with DoE and/or statistical programming skills (R, JMP, etc).
  • Technical writing skills and familiarity with formalized SOP systems, QA systems, and GMP batch records (either directly or via process transfer)
  • Knowledge of cancer biology, immunology, and/or protease biology would be beneficial
  • Experience with FACS analysis and/or developing plate-based assays would be a plus


Personal Characteristics:

  • Demonstrate a commitment to CytomX values of Integrity, Commitment, Creativity, Teamwork, Accountability and Fun
  • Candidates must be able to work independently, while also collaborating fluidly with cross-functional project teams


CytomX is an equal opportunity employer. Employment decisions are based on merit and business needs. CytomX will not discriminate against any job applicant because of race, color, national origin, ancestry, gender, sexual orientation, age, religion, creed, physical or mental disability, gender identity, medical condition, pregnancy, marital status, veteran status, or any other characteristic protected by federal, state or local law.