Sr. Research Associate, Cell Assays

91016, Monrovia
May 25, 2021
Required Education
Bachelors Degree
Position Type
Full time

Xencor is an innovative, clinical-stage biotechnology company located in the Los Angeles area (near Pasadena) and in San Diego. We use our pioneering XmAb® technology to discover and develop better biotherapeutics – antibodies and other proteins with improved function – with the goal of improving patient outcomes and quality of life, and we have an excellent opportunity for a Senior Research Associate (RA III) with Cell Assay experience to join our team.

Our protein engineering capabilities and the modular nature of our technology allow us to quickly identify and create new platforms and drug candidates for potential development. We are developing a broad portfolio enabled by the rapid expansion of our bispecific technologies, and nine XmAb bispecific antibodies and cytokines are in clinical testing. We also leverage our many XmAb technologies by engaging in multiple collaborations with leading global biopharmaceutical companies, including Novartis, Amgen and Genentech, among others. Including our partners, over a dozen XmAb drug candidates are advancing through clinical development, and the first antibody that incorporates an XmAb technology has been approved for commercial marketing worldwide.


Our employees are the most important factor in our success and we have assembled a highly talented group from diverse backgrounds and disciplines to execute our business plan and shape our future. Xencor employees value new ideas and flexibility and demand from each other scientific rigor, a passion for innovation, and a willingness to take risks



  • Support the discovery and antibody characterization process in the Biophysical and Bioanalytical Characterization team through library screening using flow cytometry and ELISA assays.
  • Generate and maintain transient and stable cell lines.
  • Instrument maintenance and general lab duties



  • BS/MS in Biochemistry, Biology or related field is required
  • Previous experience in a biotech environment is a strong plus
  • Strong hands-on experience with cell culture, transient or stable cell line generation, flow cytometry, and high-throughput cell binding assay design is a requirement.
  • Experience screening crude supernatants (phage, periplasmic extracts, hybridoma supernatants, serum etc.)
  • Experience with B and T cell isolation from PBMCs or tissue
  • Hands on experience with ELISA or other high-throughput plate-based binding/activity assays
  • Good knowledge and familiarity with protein handling and conjugation
  • Experience with high throughput liquid handling is a plus
  • Familiarity with SPR or BLI methods for protein titer and activity assays is a plus
  • Perform instrument maintenance and other lab duties including inventory, ordering, sample management etc.
  • Excellent time management, record keeping and organizational skills.
  • Self-Motivated, strong inter-personal and communication skills.
  • Ability to work in a dynamic and fast-paced environment.



We strive to create an environment that will challenge, motivate, and reward our employees for meeting the changing demands of creating breakthrough therapeutics. Xencor has a highly collaborative structure that integrates co-workers with different skill sets into teams for product and technology development.  With an emphasis on attaining the best and most highly qualified candidates in their respective fields, we offer a competitive salary & benefits package. 


Physical Demands:
The physical demands described are representative of those that must be met by an employee to successfully perform the primary functions of this position.


The physical demands of the office are normally association with extended amounts of time sitting and using office equipment, including a computer, keyboard and mouse, which can cause muscle strain. While performing the duties of this job, the employee is frequently required to stand, walk and sit. Periodic light lifting of supplies and materials may apply. Work is performed in an office environment.


 Americans with Disabilities Act (ADA) Statement

The Company will provide reasonable accommodations (such as a qualified sign language interpreter or other personal assistance) with the application process upon your request as required to comply with applicable laws. If you have a disability and require assistance in this application process, please contact


To perform this job successfully, an individual must be able to perform each essential duty satisfactorily. Reasonable Accommodations may be made to enable qualified individuals with disabilities to perform the essential functions.


Equal Employment Opportunity (EEO) Statement

The Company is an equal opportunity employer, and all qualified applicants will receive consideration for employment without regard to age, race, color, religion, sex, sexual orientation, gender or gender identity, national origin, disability status, protected veteran status or any other characteristic protected by state or federal law.


Xencor does not accept profiles or resumes from recruiting vendors without a binding written agreement. Any unsolicited submission of services and or resumes in no way creates an obligation or duty by Xencor, implied or otherwise.