Our Team

Joseph Baur, Ph.D.

 Dr. Baur maintains an active research program that involves extensive metabolic phenotyping in rodents. Major interests in the lab include the consequences of altered nicotinamide adenine dinucleotide metabolism, effects of caloric restriction (CR) and CR-mimetic drugs, and the use of isotopic labeling of precursors to assess metabolic flux. Dr. Baur oversees all aspects of the core and provides long-term strategic direction.

Paul Titchenell, Ph.D.

Dr. Titchenell maintains an active NIH-funded research program that is driven by in vivo rodent physiology and metabolic phenotyping. Dr. Titchenell’s laboratory is focused on the control of metabolism by hormones and nutrients with a particular focus on the molecular mechanisms of insulin action and insulin resistance. Dr. Titchenell’s laboratory takes advantage of the latest experimental techniques in rodents including the use of labelled metabolites to define the systemic control of glucose, lipid, and protein metabolism. In cooperation with Dr. Baur, Dr. Titchenell provides strategic oversight and manages all aspects of the core.

Corey Holman, Ph.D.

Dr. Holman has over 8 years of experience working with metabolic phenotyping in rodents. She started her career as a research technician in the Weill Cornell Medicine Metabolic Phenotyping Center, then received her Ph.D. at the University of Pennsylvania in the laboratory of Dr. Patrick Seale. Dr. Holman’s thesis work on thermogenic adipose tissue focused on understanding the contribution of adipocyte precursor cells and adipocyte subpopulations to the aging-induced decline in beige adipose tissue development. Throughout her doctoral studies, Corey also ran and maintained the metabolic cage system for the Institute for Diabetes, Obesity and Metabolism. Dr. Holman is excited to not only bring her expertise in metabolic phenotyping to assist the UPenn and greater Philadelphia community (and beyond!) with experiments, but also develop and integrate new techniques into the RMPC and help advance the rodent metabolic phenotyping field as a whole. Please reach out to Corey if you would like to schedule an experiment!

Qingwei Chu, M.D, M.Sc

Dr. Chu has more than 20 years of experience handling rodents. She is a highly skilled surgeon and routinely performs arterial and venous catheterizations to support infusion studies (including glucose clamps) with both radioactive and stable isotope tracers. In addition, she performs implantations to support telemetric monitoring and develops new surgical procedures to facilitate unique experimental designs.

Michelle Lee

Michelle has over 5 years of experience in animal handling and husbandry and is a Research Specialist who assists in executing all core experiments in the RMPC. Michelle is also the core’s point Promethion Metabolic Cage technician having attended Sable System International’s High-Resolution Metabolic and Behavioral Phenotyping Course in May 2024. Michelle first joined Penn’s University Lab Animal Resources department in 2020, and during her time at ULAR, Michelle became nationally certified as an AALAS Registered Assistant Laboratory Animal Technician (RALAT). Michelle is currently enrolled in Penn’s College of Liberal & Professional Studies, pursuing her bachelor’s degree of Applied Arts and Sciences with a concentration in Physical and Life Sciences part-time.

Jane Touch

Jane is a Research Specialist and is completing her Wistar Institute's Fox Biomedical Research Technician Apprenticeship here in the RMPC. Jane began her scientific journey at the Community College of Philadelphia, where she earned an associate degree in biology. She then gained valuable hands-on laboratory experience through the Biomedical Technician Training Program at the Wistar Institute. Currently, Jane is expanding her skillset and plays a crucial role assisting in executing all core experiments in the RMPC.

Samantha Tomlinson

Samantha is a Research Specialist in the RMPC and has over 3 years of experience working with laboratory rodents. After obtaining a bachelor’s degree in Animal Biotechnology and Conservation, Sam began her laboratory career as a study technician for the rodent toxicology department at the major CRO, Covance. Here, she gained experience performing a variety of dose administration techniques and biological sample collections and obtained her ALAT/LAT certifications. Now Sam assists in performing all experiments in the RMPC, were above all else, she takes pride in consistently observing the animals for signs of pain, distress, or illness to help maintain a high standard of animal welfare.

James Davis, Ph.D.

Xiaoyan Yin, M.D

Dr. Yin brings over 15 years of expertise in rodent handling, surgeries, metabolic equipment utilization, and testing. Her skills encompass all services offered by the RMPC, with particular expertise in arterial and venous catheterization for hyperinsulinemic-euglycemic glucose clamps, lateral cerebral ventricle cannulation, Alzet miniosmotic pump implantation, intra-duodenal catheterization, muscle strength and coordination evaluations, DSI telemetry monitoring.​