Research Associate II/ Sr. Research Associate, Protein Purification

Developing innovative therapies is one of the most challenging, most essential and personally rewarding fields in science. This is the most exciting time to be a part of Astellas, a company with a uniquely collaborative and patient-focused culture.

There’s something special about working at Astellas. It’s reflected in our focus on the people we serve, the way we treat each other and the results we achieve together as a company.

Astellas is announcing a Research Associate II/ Sr. Research Associate, Protein Purification opportunity at their Xyphos site in South San Francisco, CA.


The primary purpose of this role is to support all protein production, purification, and quality control assay needs. This position will work primarily in a laboratory setting with Scientist and R&D teams. If candidate skillset is extended to operational sufficiency with Akta chromatography and Octet kinetic analysis systems then would qualify for Sr. Research Associate role.

Essential Job Responsibilities:

  • Culturing and maintenance of established cell lines; transfection of DNA into cell lines for target protein expression
  • Demonstrated competency with standard protein purification strategies (e.g. protein A, Ni-NTA purification, on-column protease cleavage strategies).
  • DNA purification as part of the protein expression work-flow; additional molecular biology experience (e.g. PCRs, molecular cloning) a plus.
  • Protein analysis competency in areas of SDS-PAGE, Western blotting, ELISA binding assays.
  • Operational familiarity with Akta chromatography systems and protein kinetics systems like the Octet a significant candidate advantage.
  • Strict adherence to established standard protocols for reliable and consistent protein production.
  • Performs experiments independently with careful attention to detail, accurately records procedure/data/results in a timely manner, notes and reports experiments/results that may be out of trend.
  • Interprets data, draws conclusions from experimental work, and presents in team meetings.
  • Collaborates with other members of the R&D team, with other teams within Xyphos.
  • Involved with R&D laboratory management and operation.
  • Performs other duties as assigned or special projects as needed.



  • BS degree with 3+ years or MS with 0-2 years of laboratory experience
  • Experience with mammalian cell cultures
  • Proficiency in mammalian protein expression systems, purification strategies, and protein analysis techniques
  • Experience expressing and purifying antibodies
  • Diligence and meticulous attention to detail in experimentation and record keeping
  • Ability to analyze and interpret data
  • Willingness to learn and enthusiasm to be part of the development of a cutting-edge therapy platform
  • Excellent organizational, time management, and problem-solving skills
  • Adaptability to meet critical production timelines
  • Ability to work independently with supervision and ability to effectively collaborate with other teams; collegiality is a critical attribute
  • Excellent communication and interpersonal skills
  • Strong work ethic with a dedicated mindset of proactively identifying and productively filling gaps
  • Ability to work weekends as needed


  • Experience with mammalian tissue culture and mammalian protein expression systems
  • Experience introducing DNA into cells by transection and subsequent protein purification
  • Experience in molecular biology
  • Sophisticated operational capabilities with Akta chromatography and Octet kinetic analysis platforms


Equal Opportunity Employer Minorities/Women/Protected Veterans/Disabled

Category Research and Development

Please apply here: