Scientist II, Antibody Discovery (Phage Display)

Xaira Therapeutics; South San Francisco (CA); On-site; USD 124,000 - 155,000; Full time

Job summary

Xaira Therapeutics in South San Francisco seeks an accomplished protein biochemist to own phage display campaigns end-to-end within our Display Technologies group, designing selection strategies, tackling difficult targets, and turning campaigns into high-quality data for antibody design models.

This high-ownership role runs campaigns, sets technical direction, mentors scientists, and collaborates with computational and engineering colleagues to scale data generation.

Qualifications

• PhD in a related field with 2–4 years of industry experience.
• Hands-on phage display library design, panning/selection and hit validation.
• Flow cytometry (FACS) experience with data interpretation and gating.
• Strong analytical skills with meticulous documentation.
• Excellent written and verbal communication; able to present complex science.

Responsibilities

• Independently design, execute, and own phage display campaigns from library through panning and hit validation.
• Develop and optimize selection strategies for challenging targets, including QC and antigen use.
• Apply library-scale approaches to measuring binder properties and scale assays for higher throughput.
• Partner with computational/ML colleagues to structure and QC data for model training.
• Mentor associate scientists and contribute to technical standards.

Skills

PhD in related field

Phage display

Flow cytometry (FACS)

Data interpretation

Scientific communication

Mammalian cell culture

SPR / BLI affinity assays

Lab automation

Python

R

Education

PhD in Molecular Biology / Biochemistry / Immunology / Protein Engineering

Tools

Flow cytometry instruments

SPR

BLI

Lab automation platforms

Python

R

Job description

About the Role

At Xaira, we're building antibody discovery engines that feed AI-driven design at scale. We're looking for an accomplished protein biochemist to own phage display campaigns end-to-end within our Display Technologies group — designing selection strategies, cracking difficult targets, and turning campaigns into the high-quality datasets that train our antibody design models.

This is a high-ownership role. You'll run your own campaigns, set technical direction, and have the autonomy to push what's possible in display-based discovery. You take pride in rigorous bench execution, think critically about experimental design, and want your data to matter beyond your own project.

Beyond your bench work, you'll help raise the group's level — mentoring associate scientists, setting technical standards, and partnering with computational and engineering colleagues to scale data generation.

Responsibilities

• Independently design, execute, and own phage display campaigns from library through panning and hit validation.
• Develop and optimize selection strategies for challenging targets, including QC and effective use of antigens across formats.
• Develop and apply library-scale approaches to measuring binder properties, and help adapt assays to higher-throughput, automated formats.
• Partner with computational and ML colleagues to generate, structure, and QC data at scale for model training.
• Mentor associate scientists and contribute to technical standards within the group.

Qualifications

• PhD in Molecular Biology, Biochemistry, Immunology, Protein Engineering, or related field, with 2–4 years of relevant industry experience.
• Significant hands‑on expertise in antibody/protein discovery by phage display — library design, panning/selection, and hit validation.
• Hands‑on flow cytometry (FACS) experience, including data interpretation and gating strategy.
• Excellent analytical and problem‑solving skills, with meticulous attention to detail and rigorous documentation.
• Strong written and verbal communication; able to present complex science to technical and non‑technical audiences.

Nice to Have

• Strong molecular biology / library construction skills (cloning, mutagenesis, assembly).
• Experience with membrane‑protein targets (e.g., GPCRs) in cell‑based or recombinant formats.
• Label‑free affinity characterization (SPR, BLI/Octet).
• Alternative display formats (yeast, mammalian, ribosome/mRNA).
• Lab automation (Hamilton, Tecan, or similar) and/or scripting for large‑dataset analysis (Python, R).
• Mammalian cell culture.

Compensation

Annual

We offer a competitive compensation and benefits package, seeking to provide an open, flexible, and friendly work environment to empower employees and provide them with a platform to develop their long‑term careers. A Summary of Benefits is available for all applicants. We offer a competitive package that includes base salary, bonus, and equity. The base pay range for this position is expected to be $124,000 to $155,000 annually; however, the base pay offered may vary depending on the market, job‑related knowledge, skills and capabilities, and experience.

Xaira Therapeutics an equal‑opportunity employer. We believe that our strength is in our differences. Our goal to build a diverse and inclusive team began on day one, and it will never end.