She earned her Ph.D. in Biochemistry at the University of Colorado in 1998, where her dissertation research focused on the catalytic mechanism employed by a bacterial enzyme involved in the metabolism of pentachlorophenol, a toxic soil pollutant. Additional post-doctoral research at the University of California-Berkeley focused on elucidating catalytic features of a vitamin B6-dependent enzyme. Subsequent to her post-doctoral studies, Dr. McCarthy spent several years teaching chemistry and biochemistry at Calvin College in Grand Rapids, Michigan.