Scientist I, Protein Production

Xaira is an innovative biotech startup focused on leveraging AI to transform drug discovery and development. The company is leading the development of generative AI models to design protein and antibody therapeutics, enabling the creation of medicines against historically hard‑to‑drug molecular targets. It is also developing foundation models for biology and disease to enable better target elucidation and patient stratification. Collectively, these technologies aim to continually enable the identification of novel therapies and to improve success in drug development. Xaira is headquartered in the San Francisco Bay Area, Seattle, and London. The Role We are seeking a highly motivated and versatile Scientist I to join our Design Hypothesis Testing team. In this role, you will drive the end‑to‑end process of recombinant protein production — from construct design and molecular cloning through expression, purification, and biophysical characterization. Your work will directly support discovery programs by delivering high‑quality protein reagents and generating quantitative insights into molecular interactions. You will collaborate closely with cross‑functional teams, including AI scientists, biologists, and assay developers, to optimize protein workflows, troubleshoot production challenges, and develop scalable, high‑throughput systems. This is an opportunity to build integrated expertise across molecular biology, protein biochemistry, and biophysical analysis within a dynamic, interdisciplinary environment. Responsibilities Design and cloning: Design and generate expression constructs (gene synthesis, codon optimization, vector cloning, mutagenesis) to support protein engineering and reagent generation. Expression: Express recombinant proteins in multiple systems (E. coli, mammalian, cell‑free, etc), optimizing yield and solubility. Purification: Purify proteins using chromatographic methods (affinity, ion exchange, size exclusion, etc) and ensure reproducibility, purity, and stability. Protein characterization: Assess protein quality (SDS‑PAGE, aSEC, etc), binding properties (BLI, ELISA, etc) and developability properties. Biophysical analysis: Design and execute binding and kinetic studies using BLI (Octet/Gator) and/or SPR (Biacore). Analyze sensorgrams, fit binding models. Optimization and troubleshooting: Identify and address challenges related to expression, aggregation, or stability, and implement optimization strategies. High‑throughput support: Contribute to automation or parallelized expression/purification workflows to enable rapid protein generation. Collaboration and documentation: Maintain rigorous ELN records, manage reagent inventory, communicate results clearly, and contribute to SOP development. Qualifications Ph.D. in Biochemistry, Molecular Biology, Structural Biology, Protein Engineering, or a related discipline with 0–2 years of postdoctoral or industry experience; or B.S./B.A. with 8–10 years of hands‑on laboratory experience in protein expression and purification. Demonstrated expertise in recombinant protein expression and purification across multiple host systems. Expertise with BLI (Octet/Gator) or SPR (Biacore) instrumentation, data analysis, and assay optimization. Proficiency in molecular cloning (PCR, Gibson, Golden Gate, mutagenesis) and expression construct design. Strong problem‑solving skills and ability to troubleshoot independently across molecular and biophysical workflows. Excellent organization, record‑keeping (ELN), and communication skills. Comfortable managing multiple projects in a collaborative, fast‑paced research environment. Preferred Familiarity with automation or high‑throughput expression/purification pipelines. Hands‑on experience with chromatography systems (e.g., ÄKTA) and analytical methods (HPLC, MS). Understanding of protein stability, aggregation, and formulation principles. Compensation We offer a competitive compensation and benefits package, including base salary, bonus, and equity. The base pay range for this position is expected to be $110,000 - $138,000 annually; however, the precise offer may vary based on experience. Xaira Therapeutics is an equal‑opportunity employer. We believe that our strength is in our differences, and we are committed to building a diverse and inclusive team. All qualified candidates are encouraged to apply; Xaira welcomes applicants from all backgrounds. We do not accept agency resumes. #J-18808-Ljbffr