Night Shift Lab Assistant Jobs in California (NOW HIRING)

We are a vibrant and intensely mission-driven team in San Francisco, comprising members from MIT, Harvard Medical School, Roche, ETH, and Dana-Farber.
We value speed and rigor, coupled with excitement, drive, and a strong work ethic. In an early-stage environment, we value people who can bring clarity to open-ended problems, take ownership of the next steps, and follow through with energy.

Capable Labs is a place for ambitious, high-integrity people who want to become dramatically better. You will be surrounded by people who care intensely about the work, get close feedback from the people making scientific and company-defining decisions, and have room to own increasingly important problems.

We believe excellent work should be met with meaningful reward, ownership, and trust. Responsibility is earned through contribution, not title alone: anyone who demonstrates the judgment, rigor, and follow-through to move important work forward can earn meaningful scope.

• Work a dedicated night-shift schedule, running chemistry workflows overnight so compounds are ready for characterization, testing, or handoff the next day.
• Execute overnight peptide synthesis workflows, including resin loading, coupling and deprotection cycles, cleavage, purification, analytical characterization, and sample preparation for testing.
• Run microwave-assisted solid-phase peptide synthesis during night-shift hours, support routine synthesizer maintenance, and help troubleshoot failed couplings, low crude purity, side products, cleavage issues, and instrument downtime.
• Purify and characterize peptide candidates using analytical HPLC, prep HPLC, LC-MS, and related methods; record identity, purity, yield, and batch-level QC data for morning handoff.
• Prepare compounds for in vitro and in vivo testing, maintain accurate experimental records, and communicate overnight synthesis results, issues, and timelines clearly to the day team.

• You are specifically looking for or open to a night-shift lab role. You are comfortable working overnight hours, operating independently during quieter lab periods, and handing off clean, well-documented work to the day team.
• You have hands-on chemistry or biochemistry lab experience and strong experimental discipline. Your education path matters less than your ability to learn quickly, and care about the quality of the result.
• You’re excited to own the overnight synthesis workflow: running reactions, purifying and characterizing compounds, documenting results, and preparing samples for testing with care and urgency.
• You are proactive and reliable when issues arise. When an instrument breaks, a synthesis fails, data look off, or a handoff is unclear, you document clearly, communicate early, and help troubleshoot toward a clean result.

• $140,000-$180,000 salary, plus equity options with an implied current value of approximately $50,000-$200,000 before exercise cost, taxes, dilution, and liquidity risk.
• Compensation will depend on the skills, experience, and scope of impact you bring. If your background, experience, or compensation needs fall outside this range, we are still open to a conversation based on the scope and impact you could bring.
• $500+ monthly wellness budget for training, supplements, coaching, recovery, or other tools that help you perform at your best.
• Healthcare: We offer a broad range of medical, dental, and vision coverage options, with Capable covering 100% of the base policy.
• You will also have access to HSA, FSA, and 401K plans.
• We support visa sponsorship where appropriate, including O-1, H-1B, J-1, TN, and other employment-based pathways. Our team is already international, with members from Canada, Pakistan, Germany, Austria, Switzerland, China, India, and the United States.

Our process is fast, transparent, and personal. We care about getting to know the person behind the application.

• Initial application
• First phone screen
• Second phone screen
• In-person work trial in San Francisco: designed to give both sides a realistic sense of working together. Get to know the founding team!