Objective: To investigate the feasibility and clinical significance of detecting the plasma membrane integrity (PMI) of sperm by SYBR-14/PI fluorescent staining and flow cytometry.
Methods: A total of 208 semen samples were divided into a normal (n = 31) and an abnormal group (n = 177), subjected to conventional computer-assisted semen analysis (CASA), and then evaluated for sperm PMI by flow cytometry after washed and SYBR-14/PI dual fluorescent staining. The percentage of sperm with PMI was indicated as that of the sperm emitting green fluorescence (SYBR-14+/PI- %).
Results: Significant differences were detected in SYBR-14+/PI- and SYBR-14-/PI+ between the normal and abnormal groups (P < 0.05), with the SYBR-14+/PI- % significantly higher in the former ([55.66 +/- 20.64] %) than in the latter ([39.71 +/- 19.21] %) (P = 0.000). The SYBR-14+/PI-% showed significant positive correlations with sperm motility (r = 0.408, P = 0.000) and the percentage of grade a + b sperm (r = 0.398, P = 0.000), and a significant negative correlation with the percentage of grade d sperm (r = -0.413, P = 0.000); the SYBR-14-/PI+ % exhibited significant negative correlations with sperm motility (r = -0.380, P = 0.000) and the percentage of grade a + b sperm (r = -0.397, P = 0.000), and a significant positive correlation with the percentage of grade d sperm (r = 0.385, P = 0.000); the SYBR-14+/PI+ % showed positive correlations with sperm motility (r = 0.172, P = 0.013) and the percentage of grade a + b sperm (r = 0.177, P = 0.011), and a negative correlation with grade d sperm (r = -0.164, P = 0.018).
Conclusion: SYBR-14/PI dual fluorescent staining and flow cytometry could be readily used to detect sperm PMI and evaluate male reproductivity.