3-D Zinc Spark Movie (VIDEO) Northwestern University This video is under embargo. Please login to access this video. Caption This movie shows zinc being released from the egg during a zinc spark. In this movie, hot spots of fluorescence at the cell surface demonstrate how groups of zinc-rich packages are released from the egg during fertilization, resulting in a zinc spark. Credit Northwestern University Usage Restrictions Credit must be used and use of caption is encouraged. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.