Job Description
Scientist II / Sr. Scientist, Protein Biochemistry, Purification
October 2025 Department: Technology Work Location: Corporate Headquarters (South San Francisco) Position Summary: TCG Labs-Soleil is looking for an experienced and passionate
Scientist II / Sr. Scientist to join our Protein Sciences group within the Biologics Technology team. In this critical role, you will design, build and optimize purification and characterization workflows for recombinant proteins across our therapeutic pipeline-advancing early-stage candidates into well-defined therapeutic molecules. You'll work hands-on at the bench with strong focus on chromatography and protein characterization, troubleshooting technical challenges, refining experimental approaches and ensure high-quality data that drives decision-making across discovery programs. Beyond the bench, as a protein expert, you will serve as a key scientific partner, bridging discovery and real-world therapeutic development. This individual contributor position offers an unique opportunity to make a visible impact, shape scientific direction, and grow into leadership roles.
Responsibilities: Design and perform purification strategies for recombinant therapeutic proteins (especially monoclonal, bispecific, multispecific antibodies, and fusion proteins), focusing on those expressed in mammalian systems (e.g., CHO, HEK), to ensure native folding, glycosylation, and therapeutic-grade quality.
- Optimize workflows (constructs, tags, buffers, resins, gradients) to reliably produce high-quality protein at mg to g scale, meeting project timelines.
- Carry out essential QC characterizations: SDS-PAGE or CE-SDS, HPLC/FPLC (ÄKTA), SEC (plus MALS / DLS where useful), endotoxin testing, and basic biophysical assays.
- Collaborate closely with Discovery Biology, Antibody/Protein Engineering, and Computational teams to supply data and material for multiple drug discovery projects simultaneously.
- Write clear technical summaries and protocols; maintain precise and up-to-date documentation to support reproducibility and regulatory needs.
- Manage CROs for protein production, method development when appropriate.
- Support purification of target proteins produced in insect, yeast and/or bacterial systems when appropriate, adapting methods to their expression characteristics and project timelines.
Qualifications: - Ph.D. degree in biochemistry, molecular biology, structural biology or a related discipline with postdoc and 2-5+ years relevant industry experience. Biotechnology and startup experience is strongly preferred.
- M.S. degree in biochemistry, molecular biology, structural biology or a related discipline 10+ years industry experience.
- Strong experience in protein biochemistry, protein purification (using affinity and traditional chromatographic techniques), protein modification using enzymatic and chemical methods, and biophysical characterization.
- Hands-on, extensive experience with instrumentation essential for protein purification, especially AKTA FPLC and Agilent or Vanquish HPLC systems.
- Extensive experience with SDS PAGE or CE-SDS, Western blotting and other protein characterization techniques.
- Hands-on experience with small scale (milligram level) protein purification either via manual gravity or spin column or HTP automated chromatography method.
- Hands-on experience with large scale (gram level) endotoxin free production of antibody and protein therapeutics.
- Optional analytics skills: BLI/SPR, DSF, intact LC-MS/peptide mapping, or capillary electrophoresis; familiarity with HTP/automation.
- Understanding of workflows spanning early discovery to IND-enabling studies.
- Familiarity of constructs design for challenging targets in various expression systems is desired, such as solid understanding of vector elements and utilization of solubility enhancing elements.
- Must demonstrate strong organizational skills with precision and attention to every detail.
- Must be able to thrive and deliver results on goals in a fast-paced, dynamic and highly multi-tasking environment.
- Must work well independently and as a member of teams in an inclusive manner.
- Must possess excellent communication and presentation skills.
Company Overview TCG Labs-Soleil, established in partnership with The Column Group, a science-focused venture capital firm, is pioneering a novel 'venture capital-biotech' model. Our core mission is to efficiently translate scientific insights into therapeutic solutions for patients facing serious diseases. This model supports scientific entrepreneurs from the initial idea to clinical proof of concept (PoC) by combining a dedicated fund (TCG Labs) with our independent, evergreen R&D center led by a top-tier scientific team (Soleil). Together, we create an integrated ecosystem that fosters the development of single-asset portfolio companies, strategically poised for transacting after clinical PoC.
For more details, visit TCGLSoleil.com and follow us on LinkedIn
EEO Statement TCG Labs-Soleil is an Equal Opportunity Employer. We do not discriminate against qualified applicants based upon any protected group status, including but not limited to race, religion, color, creed, sex (including breastfeeding and related conditions), gender identity/gender expression, pregnancy (including childbirth and related conditions), national origin, ancestry, age, marital status, military or veteran status, sexual orientation, genetic information, physical or mental disability or medical condition as defined by applicable equal opportunity laws. Any request for accommodation can be directed to [click to reveal email address] contact@tcglsoleil.com .
Benefits and Compensation TCG Labs-Soleil provides a competitive benefits package that includes access to Medical, Dental, and Vision Insurance, Life Insurance, Short and Long Term Disability, Health Savings Account (HSA), Flexible Spending Accounts (FSA), 401k plan and PTO.
The anticipated salary range for fully qualified candidates applying for this role will be $105,000 - $218,750 annually (not including discretionary bonus, equity, and benefits). The final salary offered will be dependent on several factors that include but are not limited to relevant previous experience including duration and type of experience within the industry, education, and internal equity.
Staffing Agencies TCG Labs-Soleil does not accept unsolicited agency resumes and will not pay fees to any third-party agency or firm that doesn't have a signed agreement with TCG Labs-Soleil. Please do not send agency CVs/resumes through TCG Labs-Soleil website or TCG Labs-Soleil Employees. Inquiries must be sent to [click to reveal email address] contact@tcglsoleil.com with the Subject Heading: Staffing Agency Request.
Job Tags
Full time, Temporary work, Flexible hours,