Scientist/Senior Scientist, Analytical Development & Characterization – Cell Therapy

Retro•Redwood City, CA

About The Position

Retro develops therapies for diseases driven by the biology of aging. We focus on cellular reprogramming and autophagy to broadly improve tissue function by targeting mechanisms of aging with the ultimate aim of adding 10 years to healthy human lifespan. We’re building a mission-driven team of accomplished and kind individuals who embrace our startup culture of rapid iteration, transparency, and versatility. About the Role We are seeking a new member of the Analytical Development team to drive hands-on, non-GMP analytical characterization studies for our iPSC-derived cell therapy products, including microglia and hematopoietic stem/progenitor cell programs. In this role, you will design and execute characterization studies for intermediates and drug product, with a focus on flow cytometry, functional assays, product-related impurities and variants, MoA-reflective biological activity, and IND-enabling product understanding. Your work will support QC method development, CQA definition, specification-setting, regulatory submissions, and long-term control strategy. You will report to the Head of Quality & Analytical and work closely with AD, QC, QA, and regulatory partners.

Requirements

5+ years of industry experience in analytical development, analytical characterization, or product characterization for biologics, cell therapy, or gene therapy drug products.
Hands-on expertise in flow cytometry method development and data analysis, including multiparameter panel design, assay optimization, instrument QC considerations, and characterization of product-related attributes.
Experience developing, optimizing, troubleshooting, or applying functional assays, potency-adjacent assays, or MoA-reflective biological activity assays.
Comfortable designing and executing characterization studies and interpreting results in the context of product understanding, method performance, specification-setting, or regulatory filings.
Experience working independently, prioritizing across multiple studies, and producing high-quality scientific documentation, including protocols, reports, and data packages.
Familiarity with phase-appropriate regulatory expectations for analytical characterization in support of IND submissions.
Advanced degree, PhD preferred or MS with substantial industry experience, in cell biology, biochemistry, immunology, analytical sciences, or a related life science discipline.

Nice To Haves

Experience with iPSC-derived cell therapy products, including microglia, hematopoietic stem/progenitor cells, immune cells, or other complex cell-based products.
Experience designing or executing drug product stability studies, including shelf-life, shipping, and in-use conditions.
Experience with QC vial surrogate justification, material compatibility, container closure, administration materials, or extractables/leachables-related studies.
Supported or authored characterization sections of CTD Module 3 regulatory submissions.
Familiarity with relevant regulatory guidance, including ICH Q6B, ICH Q5C, and related expectations for biologics or cell therapy product characterization.
Worked in a startup or resource-constrained environment where scientific independence, adaptability, and strong judgment were essential.

Responsibilities

Own elements of the analytical characterization strategy for intermediates and drug products, defining what needs to be measured, why, and how, to establish product and process understanding in support of the IND.
Design and execute non-GMP flow cytometry and functional characterization methods to evaluate product-related impurities, variants, and MoA-reflective measures of biological activity.
Design and execute IND-enabling characterization studies, including drug product stability (shelf-life, shipping, and in-use conditions), justification of the QC vial as a surrogate for the DP vial, and material compatibility of the DP vial and administration catheter with the drug product.
Develop, optimize, and performance-evaluate characterization methods to ensure they are scientifically sound and fit for purpose, documenting outcomes in protocols and reports.
Interpret and communicate characterization data to support CQA definition, specification setting, and regulatory justification in collaboration with the team and Head of Quality & Analytical.
Help establish best practices for characterization method development, data analysis, and documentation, raising the bar for scientific rigor across the analytical team.
Partner with AD, QC, and QA scientists and associates to connect characterization insights to QC method development and provide technical guidance where relevant.
Contribute characterization data and authored sections to IND and other regulatory submissions, ensuring accurate representation of the product and process understanding package.