Freelance Assay Development Scientist Jobs (NOW HIRING)

About Oath

Oath is a leading microbial sciences company that utilizes natural soil biology to offer innovative solutions to some of the most critical challenges facing our planet - the climate crisis and the shift to sustainable agriculture. We imagine a world where these crises are not just alleviated, but reversed, replenishing Earth's microbiomes.

Our solution has moved beyond the lab and into real-world deployment, focused on improving farmer livelihoods with teams in Rwanda, Europe, the United States, and expanding. When you join Oath, you become part of a collaborative network that prioritizes high quality scientific work. You will be working alongside trained scientists, talented commercial teams, and a broad network of partners-an ecosystem designed to help you do your best work and grow your capabilities.

We are seeking an experienced Scientist to join our dynamic, fast-paced, and supportive R&D team as our primary Analytical Assay Development Scientist. In this role, you will develop fit-for-purpose, quantitative analytical assays for live microbial products - assays used across R&D, bioprocess development, and manufacturing at Oath. You will guide the operationalization of these assays in-house and at contract research and manufacturing organizations (CROs and CMOs), helping bridge the gap between R&D breakthroughs and industrial-scale manufacturing of live microbial products that improve soil and plant health.

You will develop and validate rigorous assays to characterize microbial strains and products at every stage of their life cycle - from cultivation and fermentation, through drying, formulation, and blending, to storage and field application - measuring characteristics such as cell titers, sporulation efficiency, viability and vitality, shelf life, and colonization of the rhizosphere and plant tissues. Your work will directly inform how Oath cultivates, dries, formulates, blends, stores, and applies its microbial products, and how it understands their performance once released into the field.

Key Responsibilities

• Assay Development & Validation

  • Develop, optimize, validate, and execute quantitative analytical assays to evaluate microbial strain status and product quality throughout cultivation/fermentation, downstream processing (drying, formulation, blending), storage, and soil/seed application.
  • Characterize the precision, accuracy, and scalability of methods for quantifying live microbial titer in single-strain and multi-strain formulations.
  • Lead sample-preparation and assay optimization efforts using methods such as qRT-PCR, flow cytometry, amplicon sequencing, whole-genome sequencing (WGS), RNA-Seq, classical plate-count/CFU methods, and other microbiological and analytical techniques.

  Colonization, Persistence & Field Performance

  • Develop, validate, and oversee execution of colonization and persistence assays to assess microbial strain abundance and dynamics in the rhizosphere and on plant tissues.
  • Support efforts to connect lab-scale assay results with real-world product performance after field application.

  Technology Evaluation & Scientific Leadership

  • Maintain deep expertise in the scientific and technological literature describing the advantages and limitations of product-relevant assay types, and bring forward emerging methods with potential to improve Oath's analytical capabilities.
  • Deliver data-driven recommendations on assays, microbial strains, production methods, blending, formulation, shelf life, and application methods to cross-functional stakeholders.
  • Engage as a key thought leader in the strategic development of Oath's R&D and process development platforms.

  External Partner Coordination

  • Identify, evaluate, and coordinate with CROs, collaborators, and service providers to support assay development and execution.
  • Review external data packages and technical reports to ensure rigorous, high-quality execution consistent with Oath's standards.

  Infrastructure & Documentation

  • Implement sample tracking and automation solutions as needed.
  • Help guide development of Laboratory Information Management Systems (LIMS); thoroughly document sample tracking, processes, procedures, and operations.

  Cross-Functional Collaboration

  • Collaborate closely with colleagues in bioinformatics, data science, microbiological cultivation and testing, production/manufacturing, business development, regulatory, and field science to ensure assays meet the needs of every stage of the product life cycle.
  • As the team grows, mentor and/or manage junior scientists and research associates supporting the analytical assay function.

• Ph.D. (or equivalent experience) in Microbiology, Biochemistry, Analytical Chemistry, Molecular Biology, Microbial Ecology, or a related field.
• 5+ years of experience developing and optimizing quantitative assays for microbial-based processes and/or products.
• Extensive experience developing and operationalizing microbial assays, including optimization of assay signal-to-noise ratio, accuracy, and precision.
• Demonstrated ability to use DNA-based and other methods to quantify microbial abundance, physiological state, distribution, and activity.
• Familiarity with microbiome science, microbial physiology and life cycles (including sporulation), fermentation/cultivation, and/or agricultural yield drivers.
• Track record of designing and executing high-quality assay development plans, including experience with nucleic acid-based microbe detection and measurement approaches.
• Strong capabilities analyzing large, complex datasets using statistical methods to generate actionable, strategic recommendations.
• Demonstrated ability to critically evaluate scientific literature and translate outside innovations into in-house capabilities.
• Effective communicator of technical and organizational topics with colleagues across multiple disciplines; strong interpersonal and collaboration skills.
• Proficiency with LIMS systems (e.g., Benchling), statistical analysis and data visualization software (e.g., R, Spotfire, Tableau, JMP), and project management tools (e.g., Asana, Jira).

• 2+ years of experience developing assays for microbe-based products in a corporate R&D environment.
• Prior experience with mentorship, technical leadership, or people management.
• Experience vetting and managing CROs.
• Experience with Design of Experiments (DoE) approaches to optimizing quantitative analytical assay methods, including sample preparation protocols.
• Experience using SQL queries and relational databases.

Job Type: Full-time, non-exempt position in the United States. At this time, Oath, Inc. is not able to provide visa sponsorship or work authorization support.

Location: Vacaville, CA, 5 days a week

Compensation: $100,000 - $130000