Scientific Reports released a publication in 2016 by Francesca Duncan, PhD, Emily L. Que, PhD, Nan Zhang, PhD, Eve C. Feinberg, MD, Thomas V. O’Halloran, PhD, and Teresa K. Woodruff, PhD, entitled “The zinc spark is an inorganic signature of human egg activation.” The article describes the prominent “zinc spark,” that occurs the moment the sperm activates the egg.