PhD in chemistry, chemical biology, biochemistry, molecular biology, or related field with 0-3 years of postdoctoral or industry experience; or MS with 5+ years of industry experience.
Hands-on experience with synthesizing, purifying, and characterizing ASOs, siRNAs, or bioconjugates using automated solid-phase synthesis and chromatography.
Knowledge of ASO/siRNA therapeutic chemistry, including modifications and delivery approaches.
Strong research productivity evidenced by publications or patent filings.
Excellent written and verbal communication skills with the ability to manage multiple projects in a collaborative environment.
Willingness to work onsite at HQ in New York City.
Responsibilities
Select and manage CROs for oligonucleotide synthesis and bioconjugation, ensuring quality and timely delivery.
Design and oversee oligonucleotide conjugates, optimizing conjugation chemistry and analytical characterization.
Develop methods to confirm identity and assess purity using HPLC, LC-MS, and other assays.
Engineer AAV capsids and conduct cloning, plasmid preparation, and vector production.
Design and screen sequences or vectors with NGS readouts to enhance potency and production yield.
Collaborate with cross-functional teams to define screening cascades and support decision-making.
Support molecule advancement through process development while identifying technical risks.
Benefits
Opportunity to work in a multidisciplinary biopharma research environment.
Engagement in cutting-edge research for genetic heart disease therapies.
Collaboration with experts in cardiac, neuroscience, and non-clinical fields.
Potential for significant contributions to the discovery pipeline.
Access to advanced analytical methods and technologies.
Full Job Description
Role Summary
Lexeo is hiring a hands-on Modality Engineering Scientist to design, synthesize, and characterize oligonucleotides, bioconjugates, and AAV therapeutics for our discovery pipeline. The scientist will advance molecules from design through analytical characterization and handoff to in vitro and in vivo teams, working across chemistry, molecular biology, and pharmacology. Reporting to the Head of Cardiac Research, this role joins cardiac, neuroscience, and non-clinical scientists developing therapies for genetic heart disease and offers broad experience in multidisciplinary biopharma research.
Primary Responsibilities
Select and manage CROs for oligonucleotide synthesis and bioconjugation, including scope, vendor guidance, data review, quality, and delivery timelines
Design and oversee oligonucleotide conjugates using peptides, antibodies, or ligands; optimize conjugation chemistry, linkers, purification, and analytical characterization
Build or outsource methods to confirm identity and assess purity using HPLC, LC-MS, SDS-PAGE, spectroscopy, and other fit-for-purpose assays
Engineer AAV capsids, regulatory elements, and transgene cassettes; conduct cloning, plasmid preparation, sequencing, and research-grade vector production
Design and screen sequence or vector/capsid with NGS readouts, applying state-of-the-art analytical methods to improve potency, selectivity, and production yield
Partner with In Vitro Pharmacology, In Vivo Physiology, Analytical DMPK, and CMC to define screening cascades, interpret data, assess developability and manufacturability, select leads, and support go/no-go decisions
Support molecule advancement through process development and formulation while identifying technical risks and recommending practical experiments or external capabilities
Write SOPs, maintain and troubleshoot instruments, document work in the ELN for intellectual property and regulatory filings, present results, and monitor platform advances
Required Skills and Qualifications
PhD in chemistry, chemical biology, biochemistry, molecular biology, or a related field with 0-3 years of postdoctoral or industry experience; or MS with 5+ years of industry experience
Hands-on experience synthesizing, purifying, and characterizing research-scale ASOs, siRNAs, or bioconjugates using automated solid-phase synthesis, chromatography, and mass spectrometry
Working knowledge of ASO/siRNA therapeutic chemistry, backbone and sugar modifications, class-related toxicity, various delivery approaches
Strong research productivity demonstrated through publications, patent filings, or comparable technical contributions
Clear written and verbal communication skills, sound scientific judgment, and the ability to manage multiple projects in a collaborative, fast-paced team
Ability to regularly work onsite at our HQ in New York City
Preferred Skills and Qualifications
Industry experience in a small, fast-paced biotech is highly preferred
Working knowledge of AAV biology and vector design
Hands-on experience in AAV capsid engineering, pooled library design, and NGS data analysis
Antibody- or peptide-oligonucleotide conjugate (AOC/POC) design or linker discovery
$111,400 - $150,000 a year
Compensation is dependent on qualifications and experience
