Senior Scientist Single Cell Assay and Technology Development

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.

As a Senior Scientist on Xaira’s High-throughput Biology team, you will invent and develop single-cell assays for AI-driven drug discovery. You will create new molecular readouts and extend commercial and published technologies to measure cellular state and responses at scale. You will own development from concept and feasibility through reproducible workflows for high-throughput data generation.

Join a small, multidisciplinary technology development team where you will shape technical direction. Working with biologists, engineers, and computational scientists, you will rapidly design, prototype, and test new assays. You will help decide which ideas to pursue, which technologies to adopt, and how to expand their capabilities. The assays you build will generate data that power Xaira’s machine-learning models.

• →Conceive, prototype, and develop novel single-cell assays, and expand commercial workflows to enable new molecular readouts and biological applications.
• →Develop and troubleshoot assay components from sample preparation and barcoding through reverse transcription, amplification, targeted or whole-transcriptome NGS library preparation, and QC; design custom primers, oligonucleotides, and barcodes.
• →Build mammalian cell systems and functional assays using cell engineering, flow cytometry, imaging, and in situ hybridization.
• →Partner with biology and engineering teams to turn prototypes into reproducible, scalable workflows and document protocols for transfer to internal teams.
• →Evaluate emerging technologies.

• PhD in molecular biology, cell biology, bioengineering, biochemistry, immunology, or a related field, with 4+ years of relevant experience, including industry experience in assay or technology development.
• Candidates with fewer than 4 years of postdoctoral experience, with strong single-cell assay/technology development experience, are encouraged to apply. The title can be adjusted accordingly.
• A track record of inventing or substantially improving single-cell, NGS, or cell-based assays.
• Curiosity and the ability to learn unfamiliar techniques quickly and apply them to new assay concepts.
• Expertise in molecular biology and NGS assay development, including nucleic acid handling, reverse transcription, enzymatic reactions, oligonucleotide design, and library preparation and QC.
• Experience developing or adapting single-cell sequencing workflows, with strong troubleshooting and problem-solving skills across biology, assay chemistry, instrumentation, and data.
• Strong mammalian cell biology skills, including cell culture and functional assay development.
• Strong analytical skills in experimental design and statistical analysis of NGS and single-cell data; proficiency in R or Python.
• Strong organizational skills and clear written and oral communication.
• Ability to work effectively in a fast-paced, rapidly changing environment.

• Antibody engineering, expression, QC, conjugation, or functional testing; immunology or primary immune cell assays.
• High-throughput or miniaturized assays, lab automation, or design of experiments.
• Pooled screening, genetic or chemical perturbation assays, or molecular reporter development with sequencing-based readouts.