Principal Research Associate, Protein Engineering

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 Principal Research Associate, Protein Engineering opportunity at their Xyphos site in South San Francisco, CA.


The primary focus of the Senior Research Associate position is to support molecular biology and antibody discovery efforts as a key contributor in Protein engineering team. This position will work primarily in a laboratory setting with Scientist and R&D teams.

Essential Job Responsibilities:

  • Leads research activities to the Xyphos scientific research team in molecular biology; construct design, PCR cloning, vector digestion, gel electrophoresis and Gibson assembly

  • Leads binding characterization on octet and ELISA

  • Supports phage panning and screening experiments to identify antibody binders

  • Analyzes DNA and protein sequences using DNA software and other tools

  • Maintains record in automated data workflows for sequences and experimental data

  • Maintains mammalian cell cultures and performs FACS based in-vitro assays

  • 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, provides recommendation and presents in internal and external 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 5+ years or MS with 2+ years of laboratory experience

  • Experience in molecular biology techniques, design and execution of octet and ELISA based binding assays

  • Proficiency working with DNA analyzing software and familiarity with automated data workflows

  • 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 in antibody discovery using phage, yeast display approaches

  • Experience in mammalian cell culture and FACS based in-vitro assays

Salary Range:

$99,000 - $132,000 (NOTE: Final salary could be more or less, based on experience)


  • Medical, Dental and Vision Insurance

  • Generous Paid Time Off options, including Vacation, Sick time, plus national holidays including Heritage Days, and Summer and Winter Breaks

  • 401(k) match and annual company contribution

  • Company paid life insurance

  • Annual Corporate Bonus and Quarterly Sales Incentive for eligible positions

  • Long Term Incentive Plan for eligible positions

  • Referral bonus program


Category Xyphos Biosciences

Astellas is committed to equality of opportunity in all aspects of employment.

EOE including Disability/Protected Veterans