Associate Scientist/Scientist I Protein Sciences (Cell Culture, Expression & Purification)

Soleil Labs, LLC•South San Francisco, CA

7h•$91,000 - $140,000•Onsite

About The Position

Join our innovative Protein Science team at TCG Labs-Soleil as a protein production expert! We are seeking a highly skilled, organized and motivated scientist to drive recombinant protein and antibody production across our expression and purification platforms. In this hands-on, pivotal role, you will independently design, execute, and optimize workflows spanning transient expression in HEK293 and CHO systems and high-throughput purification — delivering material across a broad range of molecule formats, from standard IgGs to complex multispecifics. You will work closely with colleagues across our expression, purification, and biology teams to interpret and communicate data, drive process improvement, advance our automation, and support our growing pipeline of protein and antibody-based therapeutics. The ideal candidate thrives in a fast-paced, collaborative environment, enjoys solving technical challenges, and brings strong hands-on expertise in mammalian cell culture and transient expression. This role is open at the Associate Scientist through Scientist I level. Title, scope, and independence will be calibrated to your experience

Requirements

B.S. with 10+ years, M.S. with 6+ years, or Ph.D. with 0–2 years of relevant experience in Cell/Molecular Biology, Biochemistry, Bioengineering, or a related field.
Strong hands-on expertise in mammalian cell culture and sterile/aseptic technique across multiple cell lines or hosts.
Demonstrated experience with transient expression in HEK293 and CHO suspension systems.
Experience producing and/or purifying multiple biologic molecule formats (e.g., IgGs, Fc-fusions); experience with multispecifics or other complex formats is advantageous.
Experience with high-throughput protein production and workflows is desirable.
Familiar with product-quality and titer analytics such as Octet/BLI and orthogonal methods.
Working proficiency in molecular biology methods supporting expression (plasmid prep, PCR, cloning, DNA QC, Geneious).
Informatics and data handling — Benchling ELN and plasmid/inventory management.
Demonstrated ability to independently design experiments, interpret and present data, and drive projects to completion.
Demonstrated ability to prioritize tasks and manage multiple projects in a dynamic, fast-paced environment.
Strong team player with excellent organization, attention to detail, documentation practices, and cross-functional communication.

Nice To Haves

General understanding of stable cell line development — pool and clone generation, single-cell cloning, selection, screening, and cell banking is a plus.
Bioreactor experience — benchtop bioreactors and/or high-throughput micro-bioreactors (e.g., Ambr 15/250), fed-batch and/or perfusion, with process-parameter control and scale-up/scale-down modeling.
High-throughput / automated purification — robotic Protein A, RoboColumns, plate-based clarification and purification — and liquid-handling platforms (Tecan, Hamilton, Beckman).

Responsibilities

Contribute and execute organization, traceability, and data integrity of high-throughput protein production workflows, including sample lineage, plate maps, inventory, experimental metadata, and results maintained in the ELN and internal databases.
Independently design, execute, interpret, and troubleshoot cell culture, expression, and purification experiments; develop and optimize production strategies across platforms and scales.
Drive transient expression platforms (HEK293 and CHO) from high-throughput (96-well) through medium-scale (1-5L) production to produce and purify a broad range of biologic formats including monoclonal IgGs, Fc-fusion proteins, and multispecific antibodies.
Maintain and expand multiple mammalian cell lines and hosts (e.g., HEK293 variants, CHO lineages), suspension and adherent as needed, under rigorous aseptic technique.
Support molecular biology efforts for protein expression, including construct design, gene synthesis coordination, cloning, plasmid preparation, and sequence verification.
Execute high-throughput purification: semi-automated Kingfisher and automated, plate-based, and liquid-handler-driven purification.
Integrate expression and purification with analytic techniques such as titer by Octet/BLI; purity and quality by SEC-HPLC, CE-SDS, SDS-PAGE).
Author technical reports, protocols, and SOPs; present results and recommendations to cross-functional teams and leadership; contribute to program and platform strategy.