At Aperian Lab Solutions, our toxicologists are available for interpretation and to answer any questions you may have.

Jerry McHan, Ph.D., DABCC
Scientific Director
Dr. Jerry McHan is a certified toxicologist with more than 30 years' experience in the field. He previously served as an associate director of Alabama Reference Lab in Montgomery; was president and laboratory director for EcoSys, Inc. in Atlanta; and spent more than 10 years with SmithKline Beecham Clinical Laboratories (now Quest), where he served as director of toxicology for the southeast region. Dr. McHan holds a Ph.D. in organic, medicinal and biochemistry from the University of Mississippi and a B.S. in chemistry and math from Berry College.

Allen Valaer, MS, TC (NRCC)
Clinical Director
Allen Valaer co-founded the Aperian Toxicology Lab after spending nearly 20 years with the Alabama Reference Lab in Montgomery as assistant director of toxicology. A certified toxicologist, he received his B.S. in laboratory technology and M.S. in medicinal chemistry from Auburn University, where he also completed coursework for a Ph.D. in medicinal chemistry. Overall, Mr. Valaer has accrued almost 30 years of experience in drug testing.

Tonya H. Mitchell, Ph.D.
Certifying Scientist
Dr. Tonya Mitchell is a certified forensic toxicologist with more than ten years' experience. She spent nine years with the South Carolina Law Enforcement Division, where she served as a special agent in the state crime lab. Dr. Mitchell holds a Ph.D. in biochemistry from the University of South Carolina and a BS in biochemistry from Auburn University.

Sreenivas Punna, M.S., M.P.H., Ph.D.
LC/MS/MS Analyst
Dr. Sreenivas Punna joined Aperian Lab Solutions in June 2008 as a LC/MS/MS analyst. He is currently spearheading the development of liquid chromatography tandem mass spectrometry methods for both forensic and clinical drug testing. Dr. Punna holds a Ph.D. in nutrition from Auburn University and received post-doctoral training in food safety and food microbiology. He also received a M.P.H. in Epidemiology from University of Alabama at Birmingham, a M.S. in Biology at the University of South Alabama, and a BS in chemistry from India. Prior to joining Aperian Lab Solutions, Dr. Punna spent 7 years teaching various courses in biotechnology, molecular biology and genetics. He has conducted research in the molecular biology of prostrate cancer and lentiviral infections.