Sr. Staff Scientist - Protein Sciences R&D (Onsite in South San Francisco, CA)SummaryTwist is searching for an exceptional R&D scientist with experience in cell biology and protein expression and purification, with an emphasis on antibodies, to lead and enhance our protein sciences capabilities.
We're looking for a curious, technically deep, and driven scientist who can operate as both a hands-on bench scientist and a builder of people and process. You will start as an individual contributor, personally executing and improving core workflows, while simultaneously defining the technical roadmap. As the team grows, you will continue to spend meaningful time at the bench and on experimental design. We are looking for people who have deep technical knowledge and a strong drive to get things done.
Job title and compensation will be determined based on several factors, including, but not limited to, the candidate's years of experience, skills, knowledge, and abilities.Key Responsibilities:- Develop small- and medium-scale antibody production workflows, including various formats (single-chain, IgG, multi-specific), culture systems, and purification methods
- Improve all aspects of the end-to-end antibody development workflow: construct design, cell line development, cell culture, purification, and analytics
- Build from the ground up and manage a team of scientists and RAs that will aid you in your work
- Independently design and execute experiments, and analyze experimental data
- Move projects forward efficiently / manage time and resources effectively / prioritize tasks in accordance with the company's goals
- Document and communicate results clearly and succinctly
- Be helpful/collaborative/proactive
- Stay up to date with new developments, companies, and technologies
- Be the ultimate subject matter expert, and understand all aspects of your work as profoundly as possible, including details that are adjacent to your projects
What You'll Bring to the Team:- Deep hands-on experience designing, expressing, and optimizing monoclonal antibodies, with demonstrated understanding of Fc structure-function relationships (effector function, stability, manufacturability).
- Proven experience with bispecific antibody architectures, including but not limited to:
- Knob-in-hole, CrossMab, common light chain, or similar
- Chain pairing control and mispairing mitigation
- Hands-on experience with antibody characterization methods, such as:
- SEC, CE-SDS
- Binding kinetics (BLI or SPR)
- Basic biophysical profiling (DSF, DLS)
- Demonstrated ability to build, improve, and standardize antibody generation workflows, not just execute existing SOPs.
- Strong mechanistic understanding of antibody biology, structure, and expression bottlenecks
- A track record of successful and creative method development
- Travel 10% of time to Portland, OR
Nice to have:- Strong understanding of transient vs stable expression tradeoffs and when to deploy each during platform development.
- Experience improving expression yields and product quality through sequence, vector, and host engineering.
- Experience developing high-throughput or semi-automated workflows for expression, purification, and screening.
- Strong understanding of platform robustness, reproducibility, and cost drivers.
- Experience generating and optimizing stable mammalian cell lines (CHO preferred):
- Vector design, promoter/selection strategies
- Clone screening, productivity optimization, and stability assessment
- Experience designing platforms that support multiple antibody modalities (mAbs, bispecifics, Fc-engineered variants)
Qualifications:- PhD in Cell Biology, Biochemistry, or a closely related field
- 8+ years of experience in protein sciences
- Hands-on experience working with antibody expression and purification
- Experience with liquid-handling systems and automation is a plus
- Familiarity with Python or equivalent programming languages is a plus
The base cash compensation for this California-based role is below. In addition to base salary, this role is eligible for bonus, equity, and a generous benefits package. Final compensation amounts are determined by multiple factors, including candidate skill, experience, expertise, and location and may vary from the amount listed above. Compensation may be different in other locations.San Francisco Bay Area Pay Range
$180,000-$232,000 USD
