Representative indication of the change in (A) PLCζ fluorescence levels and (B) Ac + Eq/dispersed localisation ratios following AUM in non-optimal (dark bars) versus optimal (light bars) parameters of sperm motility (≥40%), sperm concentration (count; ≥15 × 106 sperm/mL), and semen volume (1.5–5.5 mL). (C) PLCζ fluorescence levels and (D) Ac + Eq/dispersed localisation ratios following AUM in cases of unsuccessful fertilisation (dark bars) compared to cases of successful fertilisation (light bars). Asterisks (*, **, ***, ****) indicate a statistically significant (p ≤ 0.05) difference. Data are indicative of 100 cells examined from 55 patients each (550 cells). a.u.: arbitrary units.