Fig. 4. Acrosome reaction to ionophore challenge (ARIC) in spermatozoa obtained by swim-up (SU) and density gradient centrifugation (DGC) (n=8). Spermatozoa were capacitated at different times and challenged with calcium ionophore A23187. After evaluation of the percentage of acrosome-reacted cells in control and calcium ionophore-challenged paired-aliquots, the ARIC were estimated. ^*p<0.05 vs. SU at same incubation time.