Use of JC-1 to assess mitochondrial membrane potential in sea urchin sperm

Abstract There is a need within marine research areas for more rapid techniques to assess the health of sperm from marine invertebrates. Originating in medical research, flow cytometry has been applied to rapidly measure a range of cellular processes within a plethora of different cell types. To date, the transfer of that knowledge to marine research has been limited. A method has been developed to assess mitochondrial membrane potential (MMP) in sea urchin (Centrostephanus rodgersii) sperm using the stain 5,5′,6,6′-tetrachloro-1,1′3,3′-tetrathylbenzimidazolyl-carbocyanine iodide (JC-1) and flow cytometry. MMP is a useful indicator of sperm health as the mitochondrion is the single source of ATP production, and the driver of apoptosis. The method was carefully optimised and validated with the use of positive controls. There were strong correlations between MMP measurements and sperm swimming speed and motility (R values of 0.8–0.9, p