Job Description

We’re expanding our Protein Purification & ADC Development team!
If you’re passionate about biologics innovation and want to make a real impact, this is your opportunity to join a cutting-edge biotech in the San Francisco Bay Area.
🧪 SRA / Associate Scientist – Protein Purification & ADC Development
📍 San Francisco Bay Area | Full-Time | Onsite
Join Celltheon and help develop the next generation of biologics and ADCs.
We’re seeking a motivated, detail-oriented scientist to join our Protein Purification & Analytics team. In this hands-on lab role, you’ll contribute to the development, optimization, and scale-up of purification processes for recombinant proteins and conjugated modalities — including monoclonal antibodies, bispecifics, Fc-fusions, difficult-to-express proteins, and antibody-drug conjugates (ADCs).
You’ll collaborate closely with scientists across molecular biology, cell culture, and manufacturing to support projects from early development through GMP readiness.
🔬 Key Responsibilities
Develop/optimize 1–3 column purification workflows (SEC, ProA, CEX, AEX, HIC, IMAC, mixed modes).
Use Hamilton automation for high-throughput purification development.
Support ADC and conjugated protein purification with our bioconjugation team.
Perform analytical assays (Protein A HPLC, SEC-HPLC, CEX-HPLC, RP-HPLC, SDS-PAGE, ADC-specific methods — training provided).
Operate and maintain FPLC & analytical HPLC systems.
Document work in ELNs, batch records, and SOPs.
Collaborate with cross-functional teams to troubleshoot and solve technical challenges.
🎓 Qualifications
B.S. in Biotechnology, Biochemistry, Bioprocessing, or related field + 3–4 years industry experience (M.S. preferred).
Hands-on protein purification experience (FPLC strongly preferred).
Familiarity with analytical HPLC/chromatography methods.
Interest or experience in ADC purification/characterization desirable.
Strong attention to detail, organization, and ELN documentation.
Excellent teamwork and communication skills.
💡 About Celltheon
Celltheon Corporation is a biotechnology company in the San Francisco Bay Area pioneering advanced expression and ADC development technologies.
Our proprietary platforms — OmniCHO™ for transient expression, Goldilocks™ Transposase for stable cell line development, and SUPER CELL™ CHOK1 for difficult-to-express proteins — deliver high titers, exceptional quality, and rapid timelines.
We offer end-to-end solutions from molecular design through manufacturing-scale processes, including bioconjugation services for ADCs.
At Celltheon, you’ll work in a collaborative, fast-paced environment where creativity is encouraged, challenges are welcomed, and your contributions make an immediate impact.
📩 Apply Today: info@celltheon.com