Medical Staff Experts

John Asplin, MD

Medical Director Consultant

Dr Asplin is board certified in internal medicine and nephrology. He graduated with a BA from the College of the Holy Cross and obtained his medical degree from Emory University School of Medicine. Dr Asplin completed his residency in Internal Medicine at the University of Cincinnati Medical Center. He then spent three years in the Navy Medical Corps before doing his nephrology fellowship at the University of Chicago.

After fellowship, Dr Asplin joined the faculty at the University of Chicago Medical School, where he pursued clinical and research interests in kidney stone disease. In 2000, he joined Litholink Corporation as medical director, a position he continues to hold. Litholink became a subsidiary of LabCorp in 2007. At Litholink, Dr Asplin oversees the medical aspects of the kidney stone program, including creation of medical algorithms for interpretation of urine chemistries and providing consultation to physicians who have questions about their kidney stone patients. He provides medical support for the creation of Clinical Decision Support products and directs a busy research program focused on kidney stone disease. Dr Asplin continues his teaching duties at University of Chicago. Dr Asplin has published over 80 peer-reviewed articles, as well as numerous book chapters. He is on the editorial board of American Journal of Nephrology and Urolithiasis. 

Sara Best

Medical Director

Dr. Best is a board certified urologist. She obtained her medical degree at the University of Wisconsin School of Medicine and Public Health, where she went on to do her residency training in Urology. She went on to do a fellowship in Endourology and Minimally-Invasive Urology at the University of Texas – Southwestern in Dallas.

Upon completion of fellowship, Dr. Best joined the faculty at the University of Wisconsin School of Medicine and Public Health, where along with her clinical and research focus on nephrolithiasis, she served as co-director of the Endourology Fellowship program. She continues to hold her appointment at UWSMPH, operating at the VA Hospital and directing the Simulation Education Program for the Department of Urology. In 2023, she joined LabCorp as medical director, where she contributes her clinical experience to the medical aspects of the kidney stone program. She helps create the unique Clinical Decision Support report for Litholink, provides consultations to providers managing stone patients, and develops content to support the educational mission of the company.

Dr. Best has published over 110 peer-reviewed articles and numerous book chapters, and serves on the editorial board of the Journal of Endourology.