Senior​/Principal Scientist, Analytical & Bioanalytical Chemistry

We are seeking a Senior/Principal Scientist to lead the bioanalytical/analytical characterization of our oligonucleotide therapeutics. The role blends strong mass spectrometry capability with a broader bioanalytical and pharmacokinetic remit: you will develop and apply LC–MS/MS and LC–HRMS methods to quantify drug exposure and characterize stability and metabolism and connect those analytical results to pharmacokinetic and pharmacodynamic understanding.

You will work across the analytical workflow — from analyzing and extracting oligonucleotides out of plasma and complex tissues, through method development and data interpretation, to translating findings for project teams. It is a hands-on role that also carries technical influence: guiding method strategy and helping more junior scientists grow.

This role will require full-time onsite work at our research facilities in South San Francisco.

The pay range for this position at commencement of employment is expected to be between $150,000–$180,000 per year depending on experience. Base pay offered may vary depending on other factors, including job-related knowledge, skills, and experience. The total compensation package for this position may also include equity in the Company, a discretionary annual bonus, and a full range of healthcare and other benefits, including 401(k) eligibility and paid time off (including vacation, sick time, and parental leave).

Details of participation in these benefit plans will be provided if a candidate receives an offer of employment.

If hired, the employee will be in an “at-will position” and the Company reserves the right to modify base salary (as well as any other discretionary payment or compensation program) at any time, including for reasons related to individual performance, Company or individual department/team performance, and market factors.

• Bioanalytical Method Development:Develop and optimize LC–MS/MS and LC–HRMS methods for the quantitative and structural analysis of oligonucleotides and their metabolites across biological matrices, applying ion-pairing and HILIC chromatography as appropriate.
• Mass Spectrometry:Apply triple-quadrupole and high-resolution (Orbitrap) mass spectrometry for quantification, accurate-mass confirmation, and metabolite identification; troubleshoot chromatographic and mass-spec performance to keep assays robust.
• Tissue Extraction & Sample Preparation:Design and troubleshoot extraction workflows to recover oligonucleotides from plasma and challenging tissues (e.g., liver, kidney, muscle, CNS), including homogenization, solid-phase, and liquid–liquid extraction that maximize recovery and minimize matrix effects.
• Technical Guidance:Help shape bioanalytical method strategy for the oligonucleotide portfolio and provide technical mentorship to junior scientists and associates, sharing best practices at the bench.
• Cross-Functional Collaboration:Partner with Discovery Chemistry, in-vitro and in-vivo teams to connect analytical readouts to biology and inform molecule and study design.
• Data Integrity & Communication:Maintain rigorous, well-documented, reproducible data; author method summaries and study reports and communicate findings clearly to inform decisions.

• Ph.D. in Analytical Chemistry, Biochemistry, Chemistry, or a related field, with relevant bioanalytical experience (or M.S. with commensurate hands-on experience).
• Strong hands-on expertise developing and running LC–MS/MS and high-resolution mass spectrometry methods for quantitative bioanalysis.
• Experience with the bioanalysis of oligonucleotides (e.g., ASOs, siRNA), or a demonstrated ability to apply MS and bioanalytical expertise to novel analytes.
• Experience extracting and quantifying analytes from complex biological matrices, including plasma and tissue homogenates.
• Ability to provide technical guidance and mentorship in a collaborative, cross-functional environment.
• Excellent problem-solving, data-integrity, and written/verbal communication skills.

• Experience with ion-pairing reversed-phase and HILIC chromatography for oligonucleotides.
• Familiarity with chemically modified…