Sr. Associate Scientist I - Microbiologist

At RayzeBio, every day is an opportunity to ignite meaningful change. As a wholly-owned subsidiary of Bristol Myers Squibb, RayzeBio blends the nimble, pioneering spirit of an emergent biotech with the global expertise and resources of a leading innovator in oncology. Our mission is to develop transformative radiopharmaceutical therapies that offer new hope for patients living with cancer. Here, you’ll join a multidisciplinary team where your ideas are valued, your expertise is amplified, and collaboration is at the heart of everything we do. From day one, expect to make an immediate impact—on our science, on our teams, and most importantly, on patients. Learn more about RayzeBio: https://careers.bms.com/rayzebio/

Job Description: Reporting to the Director of Microbiology, the Senior Associate Scientist I supports the routine operation of a Quality Control Microbiology laboratory supporting radiopharmaceutical manufacturing. This role performs routine microbiological release testing, including sterility, bacterial endotoxin, bioburden, and media qualification, in accordance with approved methods, SOPs, and cGMP requirements. The position also leads or supports method qualification/verification/validation, troubleshooting, investigations, and continuous improvement activities.

Key Responsibilities

Microbiological Testing

• Perform routine sterility testing using approved methods and isolator or cleanroom systems in accordance with current SOPs and compendial requirements

• Execute bacterial endotoxin testing (BET) using approved methodologies and ensure accurate calculation, documentation, and review of results

• Conduct bioburden testing of raw materials, in‑process samples, and drug products using membrane filtration or plate count methods as defined in approved procedures

• Perform media qualification activities, including growth promotion testing, sterility checks, and physical inspection of media lots prior to use

• Execute method qualification, verification, and validation activities with minimal supervision.

• Troubleshoot assay issues and support out‑of‑trend (OOT) evaluations to drive timely resolution.

• Support continuous improvement initiatives, including adoption of new technologies and efforts that improve data visibility.

• Flexibility to support business needs (e.g., weekend work, early starts, or late end times) may be required

Documentation & Compliance

• Accurately document all testing activities in laboratory worksheets, logbooks, and electronic systems in a right‑first‑time manner

• Review data for completeness, accuracy, and compliance with SOPs and data integrity expectations

• Flexibility to support business needs (e.g., weekend work, early starts, or late end times) may be required

• Maintain inspection‑ready documentation and support internal audits and regulatory inspections as needed

Laboratory Operations & Safety

• Maintain aseptic technique and proper gowning practices during all laboratory and cleanroom activities

• Ensure laboratory equipment, materials, and reagents are within calibration, qualification, and expiry prior to use

• Follow Environmental Health & Safety (EHS) policies and proper waste handling procedures

• Participate in routine laboratory maintenance, cleaning, and inventory activities

Training & Continuous Improvement

• Complete required GMP, safety, and method‑specific training prior to independent testing

• Collaborate effectively with peers, supervisors, QA, and cross‑functional partners

EDUCATION/EXPERIENCE/SKILLS

Education and Experience:

• BS/MS in Biology, Microbiology, or other Life Science related field with up to 3-5 years of relevant experience in production or quality control in a cGMP/FDA regulated facility.

• Experience with sterile manufacturing and/or radiopharmaceuticals strongly preferred.

Skills:

• Highly motivated and organized professional with the ability to work independently or in a team environment.

• Strong written and verbal communication skills required.

• Excellent professional ethics, integrity, and ability to maintain confidential information.

• Must be comfortable gowning in PPE to work in a cleanroom environment, working with ionizing radiation, and able to li