The Senior Associate Scientist in Assay Development at Pfizer will play a crucial role in the bioprocess and formulation development of early phase vaccines. This position requires a significant application of knowledge in the principles, concepts, and practices of the scientific discipline, making the individual a vital member of the team. The successful candidate will be proactive in contributing to team discussions and fostering a collaborative environment. The innovative scientific mindset of the candidate will be essential in helping Pfizer achieve new milestones and ultimately assist patients globally. The role is situated within the Regulated Clinical Biomarker/Flow Cytometry group, which collaborates with clinical and translational teams across Pfizer's research units. The primary focus is on developing and implementing complex flow cytometry-based biomarker assays and supportive translational/mechanistic studies for early phase clinical projects in a Good Clinical Laboratory Practice (GCLP) environment. The Senior Associate Scientist will provide technical and scientific support for biomarker data using flow cytometry (FACS), cell imaging, and related technologies for both non-regulated and regulated clinical biomarker studies that support Pfizer's drug candidates. Key responsibilities include supporting clinical flow cytometry biomarker assay development and validation, data generation and analysis, quality control (QC), and data interpretation. The individual will participate in a matrix environment with BEST/CBT teams, gaining knowledge in the development of flow cytometry and cell imaging-based biomarkers to enable Pfizer's discovery and development objectives. The role encompasses all phases of FACS laboratory operations, including technology evaluations, sample preparation, separation and detection methods, and data analysis and interpretation. All colleagues in this role are responsible for maintaining regulatory compliance appropriate for clinical study execution, including all required training as outlined in CBT Standard Operating Procedures (SOPs) and training transcripts. This includes knowledge and understanding of GLP/GCP guidance for executing preclinical and clinical studies supporting Pfizer's portfolio projects. The position also involves continuous improvement of scientific and regulatory processes through updating or creating SOPs, implementing laboratory-based processes, and developing best practices for bioanalytical data generation. Additionally, the Senior Associate Scientist will be responsible for QC and peer review of raw data, results, and final reports from colleagues within the regulated group, as well as participating in internal and external audits as needed.