McCullough was born in Naples, Italy to Betty Ann Parker and Artensel E. McCullough Sr. Her mother was a member of the United States Navy for 23 years, and McCullough thus lived in various places such as Sicily, South Korea, Japan, and Hawaii. She was later raised and completed high school in Virginia Beach, Virginia. McCullough attended South Carolina State University, where she graduated with a Bachelor of Science degree in chemistry with a concentration in radiochemistry and served as the school's 75th Miss South Carolina State University. While a student, she was a member of the American Chemical Society, the Health Physics Society, and the American Nuclear Society. She has been inducted into the Golden Key International Honour Society and the National Society of Black Engineers.