Scientist – Protein Purification and Characterization

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Scientist, Protein Purification and Characterization

Sunflower Therapeutics PBC
Medford, MA  | Full-time
Start Date: June 2023

Position overview. Sunflower Therapeutics is currently recruiting a motivated and highly organized individual to support its mission to deliver protein manufacturing solutions that anyone can use for creating innovative new medicines, food products, and other bio-based products. Sunflower is advancing “right-sized” and efficient approaches to democratize protein manufacturing using strain engineering, integrated process development, and automated small footprint facilities. Reporting to the Director of Research and Development, the Protein Purification and Characterization Scientist will be responsible for developing, optimizing, and evaluating processes to purify recombinant proteins from yeast culture, including assessment of expressed protein quality using biophysical and functional characterization. This individual will engage in research activities to support the development of processes for benchtop and pilot scale manufacturing platforms, including but not limited to: development, optimization, and characterization of chromatographic purification methods for recombinant proteins and development and routine performance of techniques for protein quantification and characterization (SDS-PAGE, ELISA, HPLC, etc). As Sunflower grows, the Protein Purification and Characterization Scientist will contribute to the continuous improvement of Sunflower’s purification and protein analytical capabilities.



  • Develops protein purification processes, including integrated (straight-through) chromatographic processes, through modern techniques
  • Purifies proteins using common chromatography methods (ion exchange, hydrophobic interaction, multimodal) using FPLC and/or high-throughput platforms
  • Develops and performs analytical techniques such as SDS-PAGE, ELISA and HPLC to characterize protein identity, purity and function
  • Troubleshoots and optimizes methods for purification and protein characterization
  • Maintains laboratory equipment, space, and supplies related to purification
  • Designs, implements and maintains standard operating procedures and data records
  • Communicates experimental planning and results with both internal and external stakeholders
  • Supports writing of reporting documents, technical documents, and any other necessary documentation
  • Champions innovation and drives implementation thereof to reduce the time and cost to develop processes for the manufacturing of proteins for innovators around the world



We believe the experience and capabilities outlined below will lead to success in this position. We recognize, however, that our mission to enable more proteins to reach patients and consumers worldwide is a significant challenge and will require innovative solutions. As such, we welcome all arguments for how the diversity of your training can help us reach this mission.


  • Master’s degree or higher in a relevant scientific discipline (Chemical Engineering, Bioengineering, Chemistry, Biology); OR Bachelor’s degree with at least 2 years of hands-on experience
  • 2 – 5 years of relevant experience in academic and/or industrial lab setting
  • Aligned with Sunflower’s mission
  • Prior experience with chromatographic protein purification methods (ion exchange, hydrophobic interaction, multimodal, etc) and equipment (AKTA or similar); Familiarity with tangential flow filtration preferred
  • Knowledge of protein analytical techniques (such as SDS-PAGE, ELISA, etc); Background in analytical chromatography such as SEC and RPLC preferred
  • Experience in technical writing and authoring standard operating procedures (SOPs)
  • Strong analytical and organizational skills, including meticulous attention to detail and multi-tasking capabilities
  • Enthusiastic, collaborative, and proactive attitude
  • Willingness to be a hands-on problem solver
  • Ability to easily adapt to rapidly changing company and program needs
  • Focus on continued skill-building and career development