Scientist, Peptide Chemistry

Capable Labs • San Francisco, CA

2d • Onsite

About The Position

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. About the Role You will make and characterize peptide candidates that move directly into biological testing. You will execute the full synthesis workflow—from resin loading through purification, quality control, and sample handoff—while troubleshooting failures and contributing observations that improve the next design cycle. This is a hands-on role for someone who wants close ownership of the molecules they produce.

Requirements

• Hands-on chemistry experience and strong experimental discipline; your education path matters less than your ability to learn quickly and produce high-quality results.
• Interest in owning synthesis end to end: running reactions, purifying and characterizing compounds, documenting results, and preparing material for testing.
• A creative, fast, and rigorous approach to experimental problem-solving.
• Interest in staying close to biological readouts and understanding how potency and efficacy data inform the next design cycle.
• High agency when an instrument breaks, a synthesis fails, results look unusual, or a handoff is unclear.

Nice To Haves

• Experience with solid-phase peptide synthesis, HPLC, prep HPLC, or LC-MS is valuable, but we can teach specific workflows.

Responsibilities

• Execute end-to-end peptide synthesis workflows, including resin loading, coupling and deprotection cycles, cleavage, purification, analytical characterization, and sample preparation.
• Run microwave-assisted solid-phase peptide synthesis and support routine synthesizer maintenance.
• Troubleshoot failed couplings, low crude purity, side products, cleavage issues, and instrument downtime.
• Purify and characterize candidates using analytical HPLC, prep HPLC, LC-MS, and related methods.
• Record identity, purity, yield, analytical traces, and batch-level quality-control data before handoff.
• Prepare compounds for in vitro and in vivo testing and maintain accurate experimental records.
• Share synthesis feasibility, purity, yield, stability, and analytical observations that inform what the team designs and makes next.

Benefits

• Generous equity options
• Monthly wellness budget for training, supplements, coaching, recovery, or other tools that help you perform at your best.
• Medical, dental, and vision coverage options, with Capable covering 100% of the base policy.
• HSA, FSA, and 401K plans.
• Healthy dinners with the team are provided daily.
• Visa sponsorship where appropriate, including O-1, H-1B, J-1, TN, and other employment-based pathways.

What This Job Offers

• Job Type: Full-time
• Career Level: Entry Level
• Education Level: No Education Listed