A simple zeta method for sperm selection based on membrane charge

ObjectiveThe objectives were: [1] to develop a simple zeta potential method for sperm isolation; and [2] to analyze the sperm maturity, morphology, kinematic, and DNA parameters.DesignThe phenomenon of sticky sperm adhering to slide surfaces was adapted for collecting charged sperm.SettingClinical and academic research environment.Patient(s)Discarded colloid-washed sperm from routine laboratory testing (n = 8).Intervention(s)Sperm were centrifuged in serum-free medium and collected for analyses.Main Outcome Measure(s)Kinematic parameters, DNA integrity, and maturity.Result(s)The percentages of mature (73.0% ± 0.5% vs. control 63.5% ± 0.5% SEM) and DNA intact sperm (85.0% ± 0.3% vs. 69.5% ± 0.5%) increased in the male factor subgroup. Strict normal morphology (19.3% ± 0.1% vs. 10.0% ± 0.1%), hyperactivation (7.0% ± 0.1% vs. 3.6% ± 0.1%), and progressive motility (29.1% ± 0.1% vs. 19.9% ± 0.1%) increased by twofold.Conclusion(s)The zeta method improved sperm parameters associated with increased fertilization and pregnancy after assisted reproduction procedures. Manipulation from the attaching–detaching process stimulated sperm metabolism without causing premature acrosome reactions. Total motility was unchanged suggesting a lack of association between total motility and zeta potential.