Facility Overview

Charles River’s site in Mattawan, Michigan, performs general toxicology studies and specialized studies such as DART, ototoxicity, ocular toxicology, and abuse liability. The facility also supports the development of medical devices and gene and cell therapies.

Learn How Mattawan Brings Expanded Expertise

Meet the Team

The addition of experts and scientists from MPI Research brings fresh perspectives and years of experience to our growing Safety Assessment team. Take a moment for a quick “meet and greet” with a few of our new team members.

  • Thomas Vihtelic, DVM, PhD, Director & Sr. Study Director of Experimental Therapeutics

    Thomas Vihtelic

    Thomas Vihtelic, DVM, PhD joined MPI Research in 2008 as a Study Director in Targeted Discovery Research and now serves as Director and Senior Study Director of Experimental Therapeutics. Dr. Vihtelic assists Sponsors in the design of preclinical studies in support of ophthalmology, inflammation, parasitology, and infectious disease therapies. Before joining MPI Research, he was a Research Associate Professor of Biology at the University of Notre Dame using molecular genetic strategies to study eye lens development and establishing a model of light-induced photoreceptor degeneration to characterize adult stem cell roles in the regenerating zebrafish retina. Dr. Vihtelic received a DVM from Michigan State University and a doctorate in molecular genetics from the University of Notre Dame. His doctoral research, which focused on characterization of Drosophila retinal degeneration genes, was followed by postdoctoral work at the University of Chicago (Department of Ophthalmology and Visual Sciences) and the Massachusetts Eye and Ear Infirmary (Howe Laboratory of Retina Molecular Genetics and Harvard Medical School) using mouse retinal degeneration mutants and transgenic lines. Dr. Vihtelic has presented and published in the field of experimental ophthalmology and maintains memberships in the Association for Research in Vision and Ophthalmology and American Association of Veterinary Parasitologists.

  • Rachel Tapp, MS, LATG, Sr. Study Director of Neurobehavioral Sciences

    Rachel Tapp

    Rachel Tapp, MS, LATG, is a Senior Study Director in neurobehavioral sciences at Charles River. As an expert with more than 15 years of experience, she ensures high level performance of regulatory and non-regulatory contracted neurobehavioral ototoxicity studies, focusing on study management, communication, and fostering Sponsor relationships. Ms. Tapp joined MPI Research in 2003 as a research associate and was promoted to Study Director in 2005. Before joining the company, she worked as a field research technician at the National Audubon Society and as a laboratory assistant in the Aquatic Toxicology Laboratory at Michigan State University. Ms. Tapp obtained her BS in zoology from Michigan State University in Michigan in 2002, and her MS in Pharmacology and Toxicology from Michigan State University in 2016. She has authored many auditory safety posters and articles and is an active member of the Association for Research in Otolaryngology, the Society for Neuroscience, and the Safety Pharmacology Society.