Purification Chemist

The Opportunity

We are looking for an ambitious, detail-oriented Purification Chemist to join our fast-paced RNA therapeutics lab in Cambridge. You will be central to our pipeline, purifying and characterising mRNA and chemically modified oligonucleotides to the quality our programmes demand. You will work closely with synthetic chemists, molecular biologists and formulation scientists, developing and running HPLC purification methods and delivering high-quality products. Chemist to join our fast-paced RNA therapeutics lab in Cambridge. You will be central to our pipeline, purifying and characterising mRNA and chemically modified oligonucleotides to the quality our programmes demand. You will work closely with synthetic chemists, molecular biologists and formulation scientists, developing and running HPLC purification methods and delivering high-quality products.

We are looking for a scientist with deep chromatography expertise: either a recent PhD graduate or an experienced Master’s-level chemist with a strong track record in oligonucleotide and/or mRNA purification. If you want to apply your separation science to cutting-edge RNA medicines, we would like to hear from you.

About ScionxBio

ScionxBio is engineering the next generation of RNA medicines, combining synthetic chemistry and artificial intelligence to create xRNA - a platform for long-acting therapeutics. By expanding RNA beyond nature's four-letter alphabet, we engineer molecules that sustain protein expression for weeks to months rather than days, with the durability that chronic disease demands. With an initial focus on cardiometabolic disease, we are working to turn transient treatments into durable therapies. A spinout from Eleven Therapeutics, we are an international team operating across Cambridge (UK), Tel Aviv, and Cambridge (MA), with our Cambridge (UK) site serving as our largest research and development hub, and we are proud to foster a culture of collaboration, diversity, and scientific excellence.

Key Responsibilities

• HPLC Purification: Develop, optimise and run analytical, semi-preparative and preparative HPLC methods (e.g. IP-RP, AEX, RP) to purify synthetic oligonucleotides, modified xRNA constructs and mRNA to defined purity specifications.
• mRNA Purification & Analysis: Purify in vitro transcribed mRNA and assess purity, integrity, and impurity profiles (e.g. dsRNA, truncated species, residual process components).
• Analytical Characterisation: Use HPLC and LC-MS to confirm identity, purity, concentration and structural integrity of RNA constructs, and interpret the data.
• Method Development & Troubleshooting: Optimise purification workflows for new and challenging constructs, and troubleshoot separations to improve resolution, yield and reproducibility.
• Downstream Processing: Handle post-purification steps including desalting, buffer exchange, lyophilisation, gel analysis, quantification and aliquoting.
• Instrument Care: Perform routine maintenance and system suitability checks on HPLC and LC-MS systems to keep downtime low.
• Collaboration & Documentation: Keep detailed lab notebooks, summarise results clearly, and communicate findings to chemistry and biology colleagues.

Qualifications & Experience

Essential

• PhD in Chemistry, Biochemistry or a related field (recent graduates welcome),or an MSc with substantial industrial experience.
• Solid hands-on background in HPLC purification of diverse oligonucleotides 
• Strong foundation in mRNA purification and analysis.
• Practical experience with HPLC and LC-MS instrumentation.
• Good understanding of chromatographic principles and the ability to independently develop and optimise separation methods.
• Excellent attention to detail and documentation practices.
• Strong communication and teamwork skills, with the flexibility to thrive in a fast-paced, interdisciplinary environment.
  
  

Good to have 

• Experience in the synthesis of chemically modified nucleosides/nucleotides (including di- and triphosphates).
• Experience purifying nucleosides, nucleotides or related small molecules using a range of chromatographic techniques (e.g. flash, ion-exchange, HILIC, preparative RP).
• Familiarity with capillary electrophoresis, gel electrophoresis or other orthogonal analytical methods for RNA.

ScionxBio is an equal opportunities employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. We particularly welcome applications from people who are underrepresented in the sciences.