Scientific and Administrative Team

Marc J Rumpler, PhD
Laboratory Director

Dr. Rumpler is Crestar’s full-time laboratory director and has been a practicing toxicologist for the past 15 years in clinical, forensic and research based settings. He has an undergraduate degree from Northeastern University in Toxicology and Masters and Doctorate degrees from the University of Florida in Clinical and Forensic Toxicology. He completed his postdoctoral work with the University of Florida College of Medicine Pathology Department. Dr. Rumpler has several years of experience developing and validating LC/MS based quantitative assays for drugs and metabolites. He is also licensed as a Medical Laboratory Director in the states of Florida, Georgia, New York and Tennessee.

A detailed CV may be available upon request.

Mark Rumpler

Robyn Giffin
General Supervisor, Technical Supervisor – Accessioning & Screening

Robyn Giffin joined Crestar’s Team in 2015. Robyn is a Medical Technologist, BS with 20 years of experience. Prior to Crestar, she was a Medical Technologist/Supervisor’s License (Generalist) for the Spine, Joint, and Neuromuscular Rehabilitation Center in Franklin, TN. Robyn has also served as an Instructor and Clinical Coordinator for the Medical Laboratory Technician program at Fortis University. She has 10 years of experience as a Medical Laboratory Technologist, Generalist, working in all areas of the laboratory at Dickson Medical Associates. Robyn also served at Gateway Medical Institute in Clarksville, TN for five years as a Medical Technologist. Her experience as a technologist and teaching instructor brings a wealth of testing and compliance knowledge to Crestar Labs.

Robyn Giffin

Ivan Kozekov, PhD
Technical Supervisor – Confirmation

Prior to joining the Crestar team in 2015, Dr. Kozekov was a Laboratory Manager at the Center for Spine, Joint, and Neuromuscular Rehabilitation and Laboratory Supervisor at Advanced Pain and Anesthesia Laboratory. He is one of founding member of Crestar Labs. Prior to this experience, Dr. Kozekov was a Research Assistant Professor at Vanderbilt University. Dr. Kozekov brings more than 25 years of experience in analytical method development, organic synthesis and mechanistic, physical organic chemistry and toxicology. He earned his BS, MS, and PhD degrees in Organic and Analytical Chemistry from University of Sofia “St. Kliment Ohridski,” Sofia, Bulgaria. Dr. Kozekov completed a postdoctoral fellowship in Organic, Bioorganic Chemistry and Toxicology at Vanderbilt University in Nashville, Tennessee. He is the author of more than 60 research publications and many peer-reviewed articles on synthesis, metabolism and analytical chemistry and has presented his research at national and international venues.

Ivan Kozekov

Jennifer Kunic
Technical Supervisor – Genetics

Jennifer is one of the founding members of Crestar Labs and has been managing clinical laboratories for the last two years. After completing her degree at Austin Peay State University, Jennifer entered the field of laboratory science in Dr. Huntington Willard’s laboratory in Case Western Reserve University’s Department of Genetics. While there, she designed human artificial chromosomes for use as gene therapy delivery vessels. Jennifer next moved on to the laboratory of Dr. Alfred George in Vanderbilt University’s Division of Genetic Medicine, where she expanded her research knowledge and management abilities as the laboratory manager. The research team worked to establish relationships between poorly managed illnesses, novel genetic mutations, and personalized treatment options, which is now widely known as pharmacogenomics. When given the opportunity to join Crestar Labs, Jennifer fulfilled a dream of providing patients with access into the promising world of pharmacogenomics.

Jennifer Kunic