Research Associate; Biology & Chemistry

C5R is building facilities that connect frontier AI to the physical world.

We see this connection as a force for good in expanding humanity'stech tree.

We are hiring hands-on experimentalists to run bench experiments acrossbiology and chemistry while helping build our in-house research facility inSan Francisco from the ground up.

This is not a role focused on one narrow scientific question. It is abouttwo things at once: helping AI — from LLMs to domain-specific sciencemodels — get better at doing science, and building a facility thatstands up new protocols, assays, and experiments faster and moreautonomously over time.

• Run daily facility operations, including bench organization, inventory management, sample preparation, and routine assays or measurements.
• Run synthesis and characterization workflows across biology and chemistry: cell-free and cell-based protein expression, purification, and binding characterization; small-molecule synthesis, purification, and analytical chemistry.
• Set up and integrate an ever-growing instrument stack — thermocyclers, plate readers, fluorometers, gel electrophoresis, biolayer interferometry, surface plasmon resonance, nano-DSF, mass photometry, SEC-MALS, LC/MS, benchtop NMR, automated and acoustic liquid handling, and chromatography systems — so each can be run both by hand and autonomously, as we build toward a facility that runs more and more of biology and chemistry on its own.
• Help push the frontier of what the facility can do — higher-throughput protein and antibody campaigns, enzyme and functional assays, and sequencing-based readouts — building an ever-growing protocol library.
• Troubleshoot experiments, document results carefully, and iterate alongside AI systems as the scientist in the loop.
• Source and buy equipment, reagents, consumables, and supplies; set up instruments and improve facility infrastructure as we scale.
• Work with the engineering team to improve facility systems, data capture, robotic workflows, and experimental reliability.
• Jump into a wide range of evolving responsibilities as we build the facility while operating it.

• Hands-on lab experience in at least one relevant area: biology, chemistry, biochemistry, chemical engineering, bioengineering, or a related experimental field.
• A year or more in a hands-on role — Research Associate, Associate Scientist, Lab Technician, Process Chemist, Scientist I, or similar. Undergraduates, BS or MS graduates, early PhD candidates, and people with equivalent practical experience can all be a strong fit, especially if you want to stay hands-on.
• Strong attention to detail, diligence, and pride in running experiments carefully.
• Comfort with ambiguity. We will not have standard operating procedures for everything yet, so you should enjoy turning uncertainty into a workable plan.
• Enthusiasm for doing science in a new way, and for working alongside AI systems as collaborators rather than just tools.
• Ability to work onsite in San Francisco.

• Experience working across both biology and chemistry.
• Experience in a startup, early lab, core facility, shared lab, or environment where you had to build processes from scratch.
• Interest in AI for science, self-driving labs, robotics, scientific infrastructure, or automated experimentation.
• Evidence that you can communicate clearly with engineers, scientists, and operators.

• $70,000-$100,000 annualized for full-time.
• Competitive equity package.
• Temporary stints of at least 3 months may be possible.
• This role is onsite in San Francisco only.