Associate Scientist, Microbiology
- United States - Missouri - St. Louis - Chesterfield
Why Patients Need You
Pfizer’s purpose is to deliver breakthroughs that change patients’ lives. Research and Development is at the heart of fulfilling Pfizer’s purpose as we work to translate advanced science and technologies into the therapies and vaccines that matter most. Whether you are in the discovery sciences, ensuring drug safety and efficacy, or supporting clinical trials; you will apply cutting edge design and process development capabilities to accelerate and bring the best-in-class medicines to patients around the world.
What You Will Achieve
As an Associate Scientist, you will be at the center of our operations and you’ll find that everything we do, every day, is in line with an unwavering commitment to quality. Your work in the Analytical R&D Microbiology Strategy & Testing organization helps enable development of biological therapeutics at Pfizer. Your responsibilities will be applying GMP microbiological methods (bioburden, endotoxin, PCR, etc.) in the assessment of product quality and detection of impurities. Your contributions are part of a group performing microbiology identification, testing, and method qualifications to support multiple sites in the Pfizer network. You will be responsible for Environmental Monitoring (EM) of manufacturing facilities, waters, and compressed gases at the site. The Associate Scientist is responsible for utilizing established microbiological methodologies to support GMP in-process and research & development testing of clinical supplies. You will become proficient in aseptic lab technique and facility gowning to thrive in this fast-paced environment. Your strong foundation in general scientific practice, its principles and concepts will help in meeting critical deadlines. You will be relied on as a technical contributor to assess the assigned tasks and make decisions that involve direct application of your knowledge. It is your focus and commitment that will help in making Pfizer ready to achieve new milestones and help patients across the globe.
How You Will Achieve It
- Exercise and build basic team effectiveness skills {e.g., commitment, feedback, consensus management) within the work group.
- Review and contribute to technical documents, including validation protocols and reports, analytical test procedures, investigation reports, monitoring trend reports, and change controls.
- Directly interact with multiple department team members, including presentation of data.
- Complete all Good Manufacturing Practice {part of GxP} and safety training in compliance with departmental requirements and follow appropriate safety practices in the workplace.
- Perform various experiments for microbial analysis, qualification/validation, and characterization of biological therapeutics.
- Perform and document environmental monitoring of manufacturing areas and related Microbiological activities.
- Conduct all work according to appropriate Standard Operating Procedures following Good Manufacturing Practices/Good Laboratory Practices (GMP/GLP) requirements and ensure integrity of all data generated and documented.
- Independently analyze and provide conclusions regarding data generated.
- Plan and prioritize assigned testing activities.
- Present problems and propose solutions in discussions with group members.
Education & Experience
Must-Have
- Bachelor's degree in microbiology, biochemistry, biology, or related field + 0 - 2 years of experience.
- Excellent documentation skills with high attention to detail
- Strong organizational skills and effective interpersonal and written communication skills
- Self-motivated and highly effective in a team-based environment
- Ability to follow established procedures under minimal supervision
Nice-to-Have
- 1+ years’ experience with Quality Systems in a Good Manufacturing Practices (GMP) environment
- Experience with laboratory data systems such as Laboratory Information Management Systems (LIMS)
- Hands-on experience or working knowledge in pharmaceutical industry and handling of analytical instruments
- Some knowledge of drug development process for progression of biological candidates
- Knowledge of regulatory requirements and guidelines
- Ability to manage multiple tasks and projects simultaneously
- Experience using common AI tools, including generative technologies such as ChatGPT, Gemini, Claude, or Microsoft Copilot, to support problem solving and enhance productivity.
- Demonstrated curiosity for exploring how these tools can improve outcomes and understanding of responsible AI practices, including risk management and ethical use
PHYSICAL/MENTAL REQUIREMENTS
Position requires occasional light lifting and periods of standing, sitting or walking. Laboratory testing involves repetitive operations using hand-held instruments (micropipettes).
NON-STANDARD WORK SCHEDULE, TRAVEL OR ENVIRONMENT REQUIREMENTS
This is typically a Monday-Friday schedule, first shift. Occasional weekend work or off-shift hours work is required per business need.
Candidate must be able to qualify on cleanroom gowning to conduct weekly monitoring of the manufacturing areas
Work Location Assignment: On Premise
Relocation assistance may be available based on business needs and/or eligibility.

Candidates must be authorized to be employed in the U.S. by any employer.
U.S. work visa sponsorship (such as TN, O-1, H-1B, etc.) is not available for this role now or in the future.

Sunshine Act
Pfizer reports payments and other transfers of value to health care providers as required by federal and state transparency laws and implementing regulations. These laws and regulations require Pfizer to provide government agencies with information such as a health care provider’s name, address and the type of payments or other value received, generally for public disclosure. Subject to further legal review and statutory or regulatory clarification, which Pfizer intends to pursue, reimbursement of recruiting expenses for licensed physicians may constitute a reportable transfer of value under the federal transparency law commonly known as the Sunshine Act. Therefore, if you are a licensed physician who incurs recruiting expenses as a result of interviewing with Pfizer that we pay or reimburse, your name, address and the amount of payments made currently will be reported to the government. If you have questions regarding this matter, please do not hesitate to contact your Talent Acquisition representative.
EEO & Employment Eligibility
Pfizer is committed to equal opportunity in the terms and conditions of employment for all employees and job applicants without regard to race, color, religion, sex, sexual orientation, age, gender identity or gender expression, national origin, disability or veteran status. Pfizer also complies with all applicable national, state and local laws governing nondiscrimination in employment as well as work authorization and employment eligibility verification requirements of the Immigration and Nationality Act and IRCA. Pfizer is an E-Verify employer. This position requires permanent work authorization in the United States.
Pfizer endeavors to make www.pfizer.com/careers accessible to all users. If you would like to contact us regarding the accessibility of our website or need assistance completing the application process and/or interviewing, please email disabilityrecruitment@pfizer.com. This is to be used solely for accommodation requests with respect to the accessibility of our website, online application process and/or interviewing. Requests for any other reason will not be returned.
To learn more about acceptable and prohibited uses of AI during the recruitment process, please review our candidate AI-use guidelines available on Pfizer Careers.

Research and Development
Breakthroughs that change patients’ lives
Research confirms what intuition tells us: that purpose-driven companies perform better, are more innovative, attract and retain the best people, and know how to unleash the power of those people. Pfizer’s purpose—Breakthroughs that change patients' lives—fuels everything we do and reflects our passion for building on our legacy as one of the greatest contributors of good to the world.
Each word in our purpose has meaning and reflects the value we strive to bring to patients and society:
“Breakthroughs” - These are the innovations, scientific and commercial, that we seek to deliver every day. All colleagues, regardless of role, level or location, strive for breakthroughs every day.
“Change” - We want to do more than simply improve patients’ medical conditions; we want to dramatically change their lives for the better.
“Patients’ lives” - We consider not only patients, but everyone they touch—including their families, caregivers, and friends—and everything they love to do. It’s an intentionally holistic view.
Our purpose ensures that patients remain at the center of all we do. We live our purpose by sourcing the best science in the world; partnering with others in the healthcare system to improve access to our medicines; using digital technologies to enhance our drug discovery and development, as well as patient outcomes; and leading the conversation to advocate for pro-innovation/pro-patient policies.
Every decision we make and every action we take is done with the patient in mind—and to nurture an environment where breakthroughs can thrive.
Our Values
To fully realize Pfizer’s purpose, we have established a clear set of expectations regarding “what” we need to achieve for patients and “how” we will go about achieving those goals.
The “how” is represented by four simple, powerful values—courage, excellence, equity, and joy—that define our company and our culture.
Courage: Breakthroughs start by challenging convention, especially in the face of uncertainty or adversity. This happens when we think big, speak up, and are decisive.
Excellence: We can only change patients’ lives when we perform at our best together. This happens when we focus on what matters, agree who does what, and measure our outcomes.
Equity: We believe that every person deserves to be seen, heard, and cared for. This happens when we are inclusive, act with integrity, and reduce healthcare disparities.
Joy: We give ourselves to our work, but it also gives to us. We find joy when we take pride, recognize one another, and have fun.
Pfizer Research & Development
Pfizer Research & Development serves as the beating heart of Pfizer's trailblazing product pipeline, the essence of our mission to bring life-changing medicines to the world.
With an unwavering commitment to innovation, we use a multidisciplinary approach that blends scientific expertise, cutting-edge technologies, and strategic collaborations, igniting a powerful engine that propels groundbreaking discoveries into life-saving treatments for patients in need.
Through our relentless pursuit of progress, we envision a future where cutting-edge medicines pave the way to healthier, happier lives worldwide.
Benefits at Pfizer
Pfizer offers competitive compensation and benefits programs designed to meet the diverse needs of our colleagues. Our Pay for Performance Philosophy and Practices reward colleagues based on the contributions they make to our business.
Our Competitive Benefits Programs help our colleagues by:
- Promoting Health and Wellness to help colleagues maintain and improve their physical and mental wellbeing. Pfizer offerings include health and disability insurance, preventative health programs, medical screenings, free or reduced-cost vaccinations, discounts on Pfizer products, mental health support, nutrition and fitness counseling and more.
- Strengthening Colleagues’ Financial Security by providing company contributions to retirement plans, life insurance and financial planning education to help colleagues achieve their financial goals.
- Providing Benefits and Time off for the Moments that Matter to ensure Pfizer colleagues have the time away from the office to recharge, recover and return to work as the best version of themselves. Vacation, Holiday time and Sick time are just the beginning, with a 12 week parental leave policy for both parents of a new born, 10 day of caregiver leave for those times when your family needs you whether it’s a child, spouse or parent, bereavement leave, and additional country-specific programs.
- And so much more, depending on your country and site, Pfizer offers childcare facilities or discount programs, on-site health and/or fitness centers, movement and mindfulness solutions, “Log in for your Day” work flexibility and so much more.
For U.S. based jobs, view an overview of Pfizer’s U.S. benefits program (opens in a new window)