Sr. Associate Scientist

Location: West Village

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We’re united by a mission to inspire advances in bioprocessing as a preferred partner in the production of biologic drugs that improve human health worldwide. No matter your role or background, at Repligen, you will play a key part in shaping some of the most innovative and life-changing therapies in the world. We foster a culture of purpose, collaboration, and shared success—where every voice matters and every contribution drives progress.

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The Sr. Associate Scientist is a hands-on R&D role focused on the development and evaluation of membrane-based separation technologies for downstream bio-processing, with an emphasis on ultrafiltration and tangential flow filtration (TFF) applications. This position performs laboratory and pilot scale experiments with a high degree of independence, carrying out defined experimental plans to support product and process development including concentration, diafiltration, and purification of biologics, while troubleshooting issues and generating reliable, high-quality data.

The role analyzes and interprets results, identifies performance trends, and communicates clear conclusions to support product design, scalability, and customer applications, including preparation of internal reports and supporting technical papers. Working closely with cross functional teams including R&D, Product Management, and Manufacturing, the Sr. Associate Scientist supports new product development, line extensions, and continuous improvement efforts within Repligen’s filtration portfolio.

Ability to accomplish goals with limited supervision while collaborating with colleagues and providing technical guidance as needed.

This role is expected to model our Leadership Behaviors—Integrity & Compliance, Customer Focus, Collaboration, Courage, Team Empowerment, and Accountability & Results—in all aspects of work.

Responsibilities Execute laboratory and pilot-scale experiments to support development of membrane-based filtration products, with a focus on ultrafiltration and tangential flow filtration (TFF) applications for biologics processing

Independently carry out experimental plans, including system setup, operation, and troubleshooting of filtration hardware, ensuring consistent and reliable data generation

Generate, analyze, and interpret experimental data; identify trends, assess performance, and communicate clear, data-driven conclusions

Support development of downstream bioprocessing applications including protein concentration, diafiltration, and purification across varying conditions and scales

Troubleshoot membrane, device, and process performance issues and recommend practical, technically sound solutions

Prepare internal technical reports, data summaries, and supporting white papers to document findings

Collaborate with cross-functional teams to support product development, line extensions, and continuous improvement efforts

Maintain laboratory equipment and ensure proper operation while adhering to safety practices

Provide technical guidance and collaborate across the team

Required Qualifications Bachelor’s degree in chemical engineering, Chemistry, Biochemistry, or a related scientific or engineering discipline3–5+ years of relevant industry experience in bioprocessing, filtration, or related environments

Ability to execute experiments independently and manage multiple priorities with limited supervision

Strong data analysis and problem-solving skills

Ability to work effectively in cross-functional teams

Strong written and verbal communication skills including technical report writing

Preferred Qualifications Hands-on experience with membranes, TFF cassettes (hollow fiber), ultrafiltration diafiltration, and/or tangential flow filtration (TFF) systems

Experience operating, troubleshooting, and maintaining laboratory or pilot scale equipment

Familiarity with downstream bioprocessing applications such as protein concentration, purification, or buffer exchange

Experience with membrane manufacturing development, filtration device manufacturing development, filtration device failure analysis.

Experience preparing technical reports and supporting white…