Are you an enthusiastic Nucleotide/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 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 and rare genetic disorders 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 motivated Oligonucleotide Chemist to join our team in Cambridge, UK. In this role, you will apply advanced chemical techniques to enhance RNA stability, improve cellular delivery, and help develop next-generation RNA therapeutics. Working in a collaborative, interdisciplinary environment, you will partner with chemists, molecular biologists, and AI specialists to design and optimise RNA modifications and create innovative therapeutic platforms. The ideal candidate is an agile scientist with a strong foundation in nucleic acid chemistry and hands-on experience in RNA oligonucleotide synthesis, modification, purification, and characterisation. If you are driven by scientific excellence and inspired by the transformative potential of RNA medicines, we invite you to join our efforts. Key Responsibilities Nucleoside and Nucleotide Synthesis: Design and synthesise a range of chemically modified nucleosides and nucleotides, and incorporate them into RNA through chemical or enzymatic methods Oligonucleotide Synthesis & Chemical Modifications: Plan and execute the synthesis of chemically modified oligonucleotides, including downstream processing and handling Purification & Characterization : Develop and refine purification methods (e.g., HPLC, LC-MS, PAGE) to achieve high purity and confirm the identity of modified nucleosides, nucleotides, and oligonucleotides Process Development & Scale-Up : Optimise and scale synthesis and purification workflows to improve efficiency, reproducibility, and throughput Application to xRNA: Apply oligonucleotide chemistry expertise to support xRNA synthesis, site-specific modifications, and purification for therapeutic applications Analytical Method Development: Establish and validate analytical techniques to characterise structural integrity, purity, and stability of modified oligonucleotides and xRNA constructs Troubleshooting & Optimization: Diagnose and resolve issues across synthesis, modification, purification, and analysis to enhance yield, quality, and performance Cross-Functional Collaboration: Partner 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 discipline, with postdoctoral or relevant industrial experience Demonstrated expertise in nucleotide chemistry, solid-phase oligonucleotide synthesis (SPS), and chemical modifications Strong foundation in HPLC, LC-MS, UV spectroscopy, and other analytical techniques for nucleotide/oligonucleotide characterisation Proven track record in process development and scale-up within pharmaceutical or biotechnology environments Solid problem-solving skills with the ability to optimise oligonucleotide synthesis and purification workflows Strong documentation, communication, and collaboration skills, and the ability to thrive in a fast-paced, interdisciplinary environment Good to have: Experience with enzymatic RNA synthesis, including IVT and mRNA capping strategies Hands-on experience with RNA handling and downstream processing Familiarity with mRNA delivery systems, such as LNPs