Scientist – Senior Scientist - Cell Engineering & Assay Development, Microfluidics Team

Ampersand Biomedicines is a Flagship Pioneering company on a mission to transform patients’ lives with programmed medicines that work precisely where needed, and nowhere else. We’re building a collaborative, mission-driven team that thrives in a fast-paced environment and shares a genuine desire to make a difference. We ACT our values by working with Agility to adapt and deliver impact, leading with Compassion to put people first, and practicing Transparency to build trust through openness, clarity, and integrity. At Ampersand, employees are encouraged to explore breakthrough science, take chances, support one another, and contribute ideas and perspectives openly.

The Role

Ampersand Biomedicines is seeking a Scientist - Senior Scientist (level dependent on candidate's experience) to help build and apply cell-based, high-throughput capabilities for engineered antibody and protein variant library screening. This scientist will play a central role in developing library cell systems and biological assays that enable the discovery of enhanced, engineered antibody and protein variants, while contributing to the continued evolution of Ampersand's high-throughput screening platform. A major focus will be designing reporter constructs, engineering stable pathway-responsive mammalian reporter cell systems, and developing the associated functional assays.

This role sits at the interface of molecular biology, cell biology, assay development, and microfluidic screening. The successful candidate will collaborate closely with molecular biologists on library cell vector design and generation strategies, while leading reporter-cell system and assay development. They will then partner with microfluidics engineers to integrate these biological systems and novel assays into robust high-throughput screening workflows.

The ideal candidate is a hands-on experimentalist who enjoys leading the development of new biological systems, solving challenging assay-development problems, and working across disciplines to build innovative platform technologies.

Key Responsibilities

• Collaborate with molecular biology scientists to define library-cell vector designs, expression formats, transfection strategies, cell selection approaches, and assay-readiness criteria.
• Establish workflows for transfecting, expanding, selecting, and qualifying library cell populations for downstream screening.
• Independently design, build, and qualify stable mammalian cells with controlled co-expression of a signaling receptor, an additional cell-surface target, and a pathway-responsive fluorescent reporter.
• Lead the development and optimization of biochemical and cell-based droplet-compatible assays for high-throughput screening of engineered antibody and protein libraries.
• Optimize assay performance by systematically evaluating biological and technical parameters to maximize robustness, sensitivity, reproducibility, and scalability.
• Partner with microfluidics engineers to integrate biological assays into high-throughput microfluidic screening workflows.
• Analyze and interpret experimental data to guide assay optimization, platform development, and scientific decision-making.
• Troubleshoot biological and technical challenges, optimize established workflows, and identify opportunities to improve platform performance.
• Document experimental workflows, communicate findings to cross-functional teams, and contribute to SOP development and continuous platform improvement.

Required Professional Experience & Qualifications

• PhD in Cell Biology, Immunology, Molecular Biology, Bioengineering, Biomedical Engineering, Biochemistry, Biophysics, or a related field; or MS with substantial relevant industry experience.
• Demonstrated hands-on experience designing reporter constructs and engineering and qualifying stable mammalian reporter cell lines for pathway-responsive functional assays.
• Hands-on experience in mammalian vector design and stable multi-gene cell-line engineering, including genomic integration and functional validation; Experience co-expressing multiple cell-surface proteins is particularly desirable.
• Strong hands-on experience with mammalian cell culture, cell handling, transfection workflows, cell selection, and cell-based assay execution.
• Demonstrated experience leading the development and optimization of biological assays, preferably protein-based, cell-based, or high-throughput screening assays.
• Experience with fluorescence-based detection platforms such as flow cytometry, FACS, microscopy, plate readers, or related systems.
• Experience with antibody engineering, antibody discovery, directed evolution, display technologies, recombinant protein library screening, or pooled cell-library workflows.
• Ability to design experiments, troubleshoot complex biological systems, interpret quantitative data, and make clear recommendations based on results.
• Excellent written and verbal communication skills, with the ability to work effectively across biology, molecular biology, engineering, and platform teams.
• Enthusiasm for working in a fast-paced, early-stage biotech environment, including regular collaboration with colleagues across US and European time zones.

Preferred Professional Experience & Qualifications

• Experience developing functional or cell-based assays for monoclonal antibody discovery is desirable.
• Exposure to cell-free protein synthesis or related in-vitro expression systems.
• Exposure to droplet microfluidics, single-cell screening, microfluidic sorting, or other high-throughput screening platforms.
• Familiarity with next-generation sequencing-enabled antibody screening workflows.

Ampersand Biomedicines is committed to equal employment opportunity regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity or Veteran status.

Recruitment & Staffing Agencies: Ampersand Biomedicines does not accept unsolicited resumes from any source other than candidates. The submission of unsolicited resumes by recruitment or staffing agencies to Ampersand and/or Flagship Pioneering or its employees is strictly prohibited unless contacted directly by Ampersand or Flagship Pioneering’s internal Talent Acquisition team. Any resume submitted by an agency in the absence of a signed agreement will automatically become the property of Ampersand and FSP, and Ampersand/FSP will not owe any referral or other fees with respect thereto.

The salary range for this role is as follows:

Scientist I: $100,000 - $126,500
Scientist II: $113,000 - $143,000

Sr. Scientist I: $126,000 - $159,500

Compensation and level for the role will depend on a number of factors, including a candidate’s qualifications, skills, competencies, and experience. Ampersand currently offers healthcare coverage, annual incentive program, retirement benefits and a broad range of other benefits. Compensation and benefits information is based on Ampersand’s good faith estimate as of the date of publication and may be modified in the future.