Staff / Senior Scientist, Bioconjugation Chemistry

What we are looking for in you

We are seeking a Senior or Staff Scientist, Bioconjugation to join our Chemistry team at a pivotal stage in assay development. Reporting to the Senior Director of Chemistry, you will be a hands-on expert who designs, develops, and executes bioconjugation strategies for peptide and oligonucleotide components that are central to our single-molecule proteome sequencing assay.

The ideal candidate brings deep expertise in protein and peptide bioconjugation, site-specific chemical modification of amino acid sidechains, and oligonucleotide-biomolecule conjugation, with a track record of working in complex, multi-component systems (e.g., ADCs, therapeutic bioconjugates, or new bioconjugated components for assays). A successful candidate will have an innovative method-development mindset and will effectively build new approaches to making bioconjugates. This individual will thrive in a cross-functional environment where chemical solutions must be tightly integrated into assay design.

• This role offers the unique opportunity to develop first-in-class conjugation chemistry that enables single-molecule protein sequencing.
• This is a full-time, exempt, in-person position with work conducted at our Berkeley, CA location.

What you'll do

Bioconjugation strategies

• Partner with sample prep and assay development to screen and select conjugation chemistries for peptides and oligonucleotides that enable single molecule protein sequencing
• Design bioconjugation workflows using NHS-ester chemistry, maleimides, isothiocyanate chemistry, and click chemistry (CuAAC, SPAAC, IEDDA)
• Prepare bioconjugation reagents to enable studies from proof-of-concept through prototype-kitting.

Peptide chemistry

• Develop labeling strategies based on Edman Chemistry
• Develop and apply selective C-terminal and N-terminal conjugation chemistries
• Develop site-specific labeling strategies for amino acid sidechains (Cys, Lys, Arg, Tyr, Trp, His, Asp/Glu) on native peptides. Screen protecting groups to enhance amino acid signal in the protein sequencing assay
• Enable on-bead workflow to label and release peptides for interrogation in the sequencing assay

Synthesize, characterize, and scale

• Synthesize and purify peptide and oligonucleotide conjugates for assay testing
• Characterize conjugation efficiency, purity, and stability using tools such as HPLC, LC-MS/MS, NMR, CE, UV/Vis, and FTIR
• Scale conjugate synthesis from R&D quantities to prototype-grade supply for internal testing, with attention to reproducibility, shelf-life, and fit-for-purpose quality

Collaborate and document

• Work cross-functionally with sample preparation, assay integration, and reagent manufacturing teams to troubleshoot conjugation failures and optimize workflows
• Contribute to intellectual property development through invention disclosures
• Maintain rigorous experimental documentation in Confluence and laboratory notebooks; author and maintain SOPs for new conjugation methods

What you need

Required

• MS or PhD in organic chemistry, chemical biology, biochemistry, or a related field
• Industry experience in bioconjugation chemistry, with demonstrated ability to independently design, develop, and troubleshoot conjugation workflows
• MS/PhD with 8+/6+ years of experience (for Staff Scientist)
• MS/PhD with 6+/4+ years of experience (for Senior Scientist)
• Deep expertise in protein and/or peptide bioconjugation: NHS esters, maleimides, click chemistries (CuAAC, SPAAC, IEDDA), isothiocyanate coupling, and related bioorthogonal approaches
• Experience with site-specific amino acid sidechain chemistry beyond maleimide chemistry (e.g. Cys, Lys, Arg, Tyr, Trp, Asp/Glu) for application in multistep workflows
• Track record developing novel blocking groups and conducting SAR studies to optimize blocking group performance and selectivity
• Proficiency in analytical characterization: HPLC method development, LC-MS/MS for conjugate analysis, UV/Vis, and CE
• Method-development mindset: history of building and adapting new chemical approaches rather than executing established protocols
• Demonstrated ability to function as an independent contributor and collaborative partner in a cross-functional team setting

Nice to have

• Hands-on experience with solid-phase peptide synthesis (SPPS), including protecting group strategies beyond standard Fmoc/Boc and selective on-resin modifications
• Experience with peptide C-terminal chemistry manipulation methods: thioester formation, native chemical ligation, or photoredox/iridium-catalyzed C-terminal labeling
• Familiarity with oligonucleotide chemistry and oligo-conjugation techniques (ITC, phosphoramidite modifications, click coupling to nucleic acids)
• Experience with scalable surface chemistry methods for flow cells or solid-phase supports
• Familiarity with statistical and DOE-based experimental design for chemistry optimization
• Prior experience in an early-stage biotech or tools/diagnostics company

We're looking for a teammate that

• Navigates complex team dynamics, partnerships, and challenges with creativity and logic.
• Operates with adaptability, urgency, and flexibility in evolving environments, thriving in ambiguity.
• Drives work forward without needing to be asked, taking responsibility for outcomes rather than tasks.
• Treats obstacles as problems to be creatively solved, not reasons something can't be done.
• Applies sound judgment to the best available information, testing, learning, and iterating.
• Shares early and directly when assumptions change, results are unclear, or timelines are at risk.

Work environment

• Collaborative culture where your ideas and expertise are valued
• Direct impact on product development and company direction

Professional growth

• Learn from a diverse team of world-class scientists and engineers
• Contribute to first-of-their kind technologies, high-impact publications, and patents

Compensation

Estimated Base Salary $123,000 - $187,575

This is the pay range for this position that we reasonably expect to pay. Individual compensation is based on various factors including, experience, education, skillset, and geographic location. This range is for the SF Bay Area, California location and may be adjusted to the labor market in other geographic areas.

Benefits and Perks

• Employee Stock Option Plan
• 100% Health Plan Coverage for Employees & Dependents (Medical, Dental, & Vision)
• Employer Retirement Contributions to 401(k)
• Generous Paid Time Off
• Paid Maternity and Paternity Leave
• Health & Wellbeing Program
• Office Snacks and Beverages
• Regular Team Bonding Activities