Scientist / Senior Scientist — Cell Culture, Functional Assay Development & Automation

Celltheon Corporation; San Francisco (CA); On-site; USD 80,000 - 120,000; Full time

Job summary

Celltheon Corporation in San Francisco is seeking a Scientist / Senior Scientist specialized in Cell Culture, Functional Assay Development, and Automation. This role involves developing and optimizing functional assays, authoring methods for liquid handlers, and collaborating cross-functionally. Ideal candidates have extensive experience in biomanufacturing and troubleshooting automation processes. Join an innovative team and contribute to next-generation biologics and antibody-drug conjugate testing.

Qualifications

• Deep hands-on expertise in mammalian cell culture and assay development.
• Demonstrated proficiency in writing Hamilton methods from scratch.
• Proven ability to troubleshoot and optimize automation hardware and software.

Responsibilities

• Design, optimize, and execute cell-based functional assays for biologics.
• Develop and validate ELISA and binding assays.
• Collaborate with cross-functional teams to support programs.

Skills

Mammalian cell culture

Cell-based assay development

Hamilton liquid handler methods

ELISA development

Data analysis tools

Troubleshooting automation hardware/software

Statistical reasoning

Scripting/programming skills

Education

BS/MS with 6+ years or PhD with 2+ years of experience

MS with 8+ years or PhD with 4+ years of experience

Tools

GraphPad Prism

SoftMax Pro

Excel

JMP

Job description

Job Title

Scientist / Senior Scientist — Cell Culture, Functional Assay Development & Automation

About the Role

Join Celltheon and help build the automation backbone for next-generation biologics and antibody-drug conjugate (ADC) functional testing.

We are seeking an exceptional Scientist / Senior Scientist to join our growing team with deep expertise in mammalian cell culture, cell-based functional assays, ELISA development, and laboratory automation. In this role you will design, optimize, and automate functional and potency assays that directly support candidate selection, developability, and CMC readiness.

This is a highly visible, hands‑on position ideal for someone who is equally comfortable at the bench running cell-based assays and at a workstation writing or debugging Hamilton and/or Tecan liquid handler methods. You will own the full lifecycle of automated assay workflows—from method authoring through validation and continuous improvement.

If you thrive in a fast‑paced startup environment with broad ownership, direct scientific impact, and a clear growth path into scientific leadership, this role is for you.

Key Responsibilities

• Develop, optimize, and execute cell‑based functional assays (e.g., cytotoxicity, reporter gene, ADCC/CDC, proliferation/apoptosis) for biologics and ADC candidates.
• Design and validate ELISA and MSD‑based binding and PK assays; establish fit‑for‑purpose and qualified method parameters.
• Assist cell culture team in routine CHO productions, fed‑batch experiments, and cell line development projects.
• Author new Hamilton STAR liquid handler methods from scratch using Venus including complex plate layouts, serial dilutions, hit‑picking, and multi‑step assay workflows.
• Edit, troubleshoot, and continuously improve existing automation methods to increase throughput, reduce variability, and adapt to new assay formats.
• Integrate automated liquid handling with plate readers, incubators, washers, and other peripherals to build end‑to‑end walkaway assay workflows.
• Maintain, troubleshoot, and perform routine calibration and preventive maintenance on Hamilton and Tecan platforms, including deck verification, tip tracking, and liquid class optimization.
• Develop and maintain mammalian cell lines (CHO, HEK293, Jurkat, reporter lines, etc.) used in functional assay panels; manage cell banking, thaw/expansion schedules, and passage records.
• Analyze and interpret complex dose‑response, potency, and binding data sets using software such as GraphPad Prism, SoftMax Pro, or equivalent; apply appropriate curve‑fitting and statistical methods.
• Generate high‑quality technical reports, ELN documentation, SOPs, and automation method validation packages.
• Collaborate cross‑functionally with bioconjugation, purification, analytical, and process development teams to support programs from candidate screening through GMP/CMC readiness.
• Evaluate and recommend new automation technologies, assay platforms, and software tools to expand capabilities.
• Mentor research associates and junior scientists as the team scales.

Qualifications

• Scientist: BS/MS with 6+ years or PhD with 2+ years of relevant industry experience.
• Senior Scientist: MS with 8+ years or PhD with 4+ years of relevant industry experience.
• Deep hands‑on expertise in mammalian cell culture (CHO, HEK293, Jurkat, primary cells) and cell‑based assay development for biologics or ADCs.
• Demonstrated proficiency writing Hamilton (Venus) methods from scratch, not just running pre‑built protocols.
• Strong experience with ELISA, MSD, AlphaLISA, or related ligand‑binding assay platforms.
• Proven ability to troubleshoot and optimize automation hardware and software, including liquid classes, error recovery, deck layouts, and tip management.
• Experience with cell‑based potency, cytotoxicity, reporter gene, ADCC, CDC, or internalization assays in a drug development context.
• Proficiency in data analysis tools (GraphPad Prism, SoftMax Pro, Excel, JMP, or similar) and strong statistical reasoning.
• Working knowledge of GxP, CMC development, method qualification, and tech transfer documentation preferred.
• Excellent scientific communication, documentation, and troubleshooting skills.
• Thrives in a collaborative, entrepreneurial, and rapidly evolving startup environment.

Nice to Have

• Experience with scheduling software (e.g., Green Button Go, Cellario, Overlord) for integrated work cell orchestration.
• Scripting/programming skills (Python, VBA, C#) for data pipeline automation or custom instrument control.
• Familiarity with high‑content imaging, flow cytometry, or luminescence‑based readouts in automated settings.
• Experience supporting IND‑enabling studies or GMP method transfer of cell‑based assay methods.
• Exposure to ADC‑specific functional assays (e.g., bystander killing, lysosomal trafficking, payload release).

This role offers a strong growth path into:

• Technical lead for assay automation and high‑throughput screening.
• Cell biology and functional assay sciences leadership.
• CMC / GMP bioassay and potency method ownership.

Scientists who excel in this role will have the opportunity to help shape Celltheon’s automation strategy and next‑generation biologics and ADC platform.

Why Celltheon

At Celltheon, you will work at the intersection of speed, innovation, and scientific rigor.

Our proprietary platforms — OmniCHO™, Goldilocks™, SUPER CELL™ CHOK1, and integrated ADC development services — enable rapid delivery of difficult biologics with exceptional yield and quality.