Edison State College View Institution's Website 1 article published in JoVE Biology Measuring Intracellular Ca2+ Changes in Human Sperm using Four Techniques: Conventional Fluorometry, Stopped Flow Fluorometry, Flow Cytometry and Single Cell Imaging Esperanza Mata-Martínez1, Omar José1, Paulina Torres-Rodríguez1, Alejandra Solís-López1, Ana A. Sánchez-Tusie1, Yoloxochitl Sánchez-Guevara1, Marcela B. Treviño2, Claudia L. Treviño1 1Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología-Universidad Nacional Autónoma de México, 2Math and Sciences Department, Edison State College Intracellular Ca2+ dynamics are very important in sperm physiology and Ca2+-sensitive fluorescent dyes constitute a versatile tool to study them. Population experiments (fluorometry and stopped flow fluorometry) and single cell experiments (flow cytometry and single cell imaging) are used to track spatio-temporal [Ca2+] changes in human sperm cells.