Featured Exosome Job – Scientist / Sr. Scientist, Downstream Process Development, Process Sciences

Location: Mission Bay, San Francisco, CA, USA

Mantra Bio is seeking an experienced scientist to lead downstream and purification development efforts within our process sciences group, directly supporting our exosome therapy programs. A successful applicant will have prior hands-on experience with purification method development for biologics, and be comfortable in a fast, nimble culture. Applicants should have current and extensive knowledge of biologics chromatography purification, including FPLC-based (e.g. AKTA) method and process development for affinity, ion exchange, and size exclusion chemistries. You will be a key contributor in the development of our exosome therapeutic programs and will work cross-functionally with R&D, engineers, and data scientists to rapidly establish, implement, and scale up isolation and purification methods for exosome-based therapeutic drug candidates. You are operationally minded, able to run multiple projects in parallel, and willing to do what it takes to drive the team forward.


  • Lead downstream purification process development for Mantra Bio’s exosome therapeutic development programs, currently in preclinical stage.
  • Develop FPLC-based scalable column chromatographic methods for the purification and isolation of high quality exosome products, including, but not limited to, preparatory scale affinity purification, ion exchange (IEX) chromatography, multimodal, hydrophobic interaction, and size exclusion (SEC) chromatography.
  • Execute and improve current Tangential Flow Filtration (TFF) procedure for isolation and formulation of exosome products.
  • As a subject matter expert, maintain knowledge and implement state-of-the-art technologies and processes for exosome purification and isolation.
  • Author process descriptions, SOPs, protocols, and tech transfer documents necessary for seamless process transfers to internal or external collaborators.
  • Meticulously maintain complete and accurate records of all work performed in LIMS and/or electronic lab notebook (ELN).
  • Play a central role in selection and interaction with contract manufacturers / research organizations, key suppliers, and other external vendors. Prior experience working with and managing CMO/CDMO/CRO desired.
  • Manage the downstream process development function at Mantra, including operational considerations, lab buildout and equipment purchases, team recruitment and training, setting key metrics and objectives, and providing guidance and mentorship to junior staff.
  • Coordinate tasks across multiple projects, demonstrating prioritization and planning. We are a start-up and are looking for applicants who are ready and willing to ‘roll their sleeves up’ and be the Key Driver to meet project timelines and milestones.

What We’re Looking For

  • BS/MS degree with 6+ experience or PhD degree with 3+ years experience in a drug development setting.
  • 4+ years of biologics downstream process development experience using FPLC system (e.g. AKTA)
  • Expertise in method/protocol development and scale up for biologics purification, including, but not limited to affinity, cation exchange (CEX), anion exchange (AEX), viral filtration, and tangential flow filtration (TFF) is required.
  • Familiarity with HPLC based analytical methods (SEC, RP-HPLC, ion-exchange, hydrophobic interaction chromatography, etc)
  • Prior experience with IND regulatory requirements, GMP environments, and quality documentation is highly desired.
  • Demonstrated ability to work independently with minimal supervision.
  • Familiarity with Design of Experiment (DOE) and comfortable working with analytical tools to create high quality unbiased analyses.
  • Prior experience with successful technology and process transfers to third party vendors (CRO/CDMO/CMO) is highly desired.
  • Experience mentoring, coaching, and training junior staff members is preferred.
  • Excellent interpersonal skills, including clear, succinct, and timely communication and proven ability to foster strong relationships with other team members and stakeholders.
  • Highly self-motivated and detail-oriented, with proven ability to work in a dynamic, fast-moving team.
  • Comfortable working with a data-driven team and collaborating with research scientists, data scientists and platform engineers.
  • Familiarity or experience with scripting and statistical analysis of your data.
  • Experience collaborating with computational scientists while analyzing your data.

About Mantra Bio

Mantra Bio is a biotechnology company developing exosome therapeutics for oncology and neurodegenerative disease. We are a data-first company re-imagining therapeutics from the ground up by leveraging insights from exosomes. Our team of biologists, data scientists, and platform engineers have built REVEALTM, a proprietary exosome intelligence platform enabling the discovery of exosomes therapeutics in multiple disease areas. We are proud to count 8VC, Viking, Illumina, and TenCent among our investors. Mantra Bio is a resident company of Bayer Innovation, Bayer Co-Laborator in Mission Bay, San Francisco.

Our Mission

Well Being for All.

We create exosome therapeutics that eliminate suffering and enable our global community to live well. At Mantra Bio, we believe in cultivating a principled environment of ‘Well Being’ for our team first that extends to the patients we seek to cure.


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