Are you an enthusiastic Oligonucleotide chemist with a passion for developing new technological frontiers in RNA therapeutics? Do you want to join a vibrant, creative team that will make a difference in patients’ lives? If so – look no further Job title: Oligonucleotide Chemist/Senior Scientist Location: Cambridge, United Kingdom About Eleven Tx Eleven Therapeutics is revolutionizing the field of nucleic acid therapeutics by integrating cutting-edge RNA biology, combinatorial chemistry, and artificial intelligence to generate/produce a programmable drug discovery and development platform. Our multidisciplinary team, comprising world-class scientists and entrepreneurs with a track record of breakthrough innovations, operates at the intersection of bioengineering, chemistry, genomics, and computational science. With a pipeline targeting cardiometabolic, endocrine disorders and other non-infectious diseases with significant unmet medical needs, Eleven Therapeutics is at the forefront of developing novel therapeutics. We are a global company with presence in Cambridge (UK), Tel Aviv (Israel), and Boston (US), fostering a culture of collaboration, diversity, and scientific excellence. The Opportunity We are seeking a highly skilled and passionate Oligonucleotide Chemist to join our team in Cambridge, UK. In this role, you will leverage state-of-the-art chemical techniques to enhance RNA stability, improve cellular delivery, and contribute to the development of next-generation RNA-based therapeutics. Working in a dynamic, interdisciplinary environment, you will collaborate with other chemists, molecular biologists, and AI specialists to optimize RNA modifications and design innovative therapeutic platforms. The ideal candidate is an agile scientist with a strong background in nucleic acid biochemistry and experience in RNA synthesis, modification, and characterization. If you are driven by the pursuit of scientific excellence and the transformative potential of RNA therapeutics, we invite you to be part of our groundbreaking work. Key Responsibilities Oligonucleotide Synthesis & Chemical Modifications: Design, optimize, and execute the synthesis of DNA, RNA, and chemically modified oligonucleotides using solid-phase synthesis (SPS) and other relevant methodologies. Conjugation Chemistry: Develop and implement strategies for oligonucleotide conjugation, including peptides, lipids, fluorophores, and small molecules, to enhance delivery, targeting, and functionality. Purification & Characterization : Establish and refine purification techniques such as HPLC, LC-MS, and PAGE to ensure high purity of oligonucleotide products. Process Development & Scale-Up : Lead initiatives to enhance the efficiency, scalability, and reproducibility of modified oligonucleotide synthesis and purification processes in an industrial setting. mRNA Expertise: Apply oligonucleotide chemistry knowledge to support mRNA synthesis, chemical modifications, and purification for therapeutic applications. Analytical Method Development: Develop and validate analytical methods for characterizing and assessing the stability of modified oligonucleotides and mRNA constructs. Troubleshooting & Optimization: Identify and resolve challenges in synthesis, conjugation, purification, and analysis to improve yield, purity, and performance. Documentation & Compliance: Maintain SOPs, technical reports, and regulatory documentation to ensure adherence to GMP and quality standards. Cross-Functional Collaboration: Work closely with RNA biology, formulation, and process development teams to integrate oligonucleotide chemistry into mRNA and drug development pipelines. Qualifications & Experience (Must-Have): Ph.D. in Organic Chemistry, Biochemistry, Chemical Engineering, or a related field with 3 years of industry experience; OR M.Sc. with 5 years of hands-on industry experience in oligonucleotide chemistry. Proven expertise in solid-phase oligonucleotide synthesis (SPS) and chemical modifications. Hands-on experience with oligonucleotide conjugation techniques, such as peptide-oligo, lipid-oligo, fluorophore labeling, and bioconjugation chemistries. Strong background in HPLC, LC-MS, UV spectroscopy, and other analytical techniques for oligonucleotide characterization. Experience with mRNA synthesis, purification, or chemical modifications in a research or industrial setting. Experience with process development and scale-up in a GMP, pharmaceutical, or biotechnology environment. Strong problem-solving skills with a proven ability to optimize oligonucleotide workflows. Excellent documentation, communication, and collaboration skills in a fast-paced environment. Candidates without industry experience will not be considered. Good to have: Experience with enzymatic RNA synthesis, IVT reactions, and mRNA capping strategies. Familiarity with mRNA delivery systems, including lipid nanoparticles (LNPs). Knowledge of GMP requirements for RNA therapeutics.