Doris A. Stoffers, MD, PhD

Doris A. Stoffers is a Professor of Medicine and Director of the Penn Diabetes Research Center Islet Cell Biology Core. She has extensive experience in the functional and morphological phenotyping of pancreatic islets. She oversees the strategic direction of the ICBC and is responsible for all aspects of governance.

Nicolai Doliba, DSc, PhD

Dr. Nicolai Doliba is a Research Associate Professor in the Department of Biochemistry and Biophysics and Technical Director of the Islet Cell Biology Core of the Penn Diabetes Research Center. He manages all aspects of core operation. Dr. Doliba has over thirty years of experience with islet perifusion, respirometry techniques and calcium imaging. He meets with new users to develop strategies and experimental protocols to apply to their research. Dr. Doliba also organizes workshops and provides training in a wide range of Core services including Ca2+ fluorescence and Seahorse. He has a wealth of experience characterizing the function of human islets from normal, T1D and T2D donors obtained from Dr. Naji’s Islet Resource Center at the University of Pennsylvania, as evidenced by numerous collaborative publications.

Andrea Rozo, PhD

Dr. Andrea Rozo serves as the Assistant Technical Director of the Islet Core, supporting Dr. Doliba in overseeing core operations and managing key administrative functions. Together, they engage with prospective, new, and current users to provide guidance and support. Dr. Rozo leads training in metabolic and bioenergetic assays using the Agilent XFe96 Seahorse Bioanalyzer and the Biotek Cytation 5 Cell Imaging Multimode Reader for Seahorse normalization. She also brings specialized expertise in calcium imaging, the formation and analysis of pseudoislet aggregates from human islets, and cell sorting techniques for mouse islets.

Wei Qin, BS

Wei Qin is a Research Specialist for the Penn DRC Islet Cell Biology Core. She has over 30 years of experience in procedures of rat and mouse islet isolation, tissue culture, islet cell dispersion and metabolic and secretory functional testing. She supports Dr. Doliba in the execution of islet perifusion and respirometry experiments. Wei is specialized in all procedures associated with islet cell isolation, culture and functional testing.

Jeffrey Roman, BSE

Jeffrey Roman is a Research Specialist in the Department of Biochemistry and Biophysics, with advanced expertise in perfusion techniques and hormone secretion analysis. He plays a central role in supporting experimental workflows involving dynamic tissue perfusion and endocrine function studies. In addition, Jeffrey is highly proficient with the Agilent Seahorse Bioanalyzer and contributes to user training and support for metabolic assays.

Matthew Gavin, BA

Matthew Gavin is a Research Specialist for the Penn DRC Islet Cell Biology Core. He has hands-on experience with islet culture techniques, automated liquid handler operation, and sample preparation workflows. His training includes immunohistochemistry and image scanning, supporting the generation of reliable histological data. Matthew plays a valuable role in maintaining lab efficiency and facilitating collaboration across research teams.