Human sperm selection by glass wool filtration and two-layer, discontinuous Percoll gradient centrifugation

Area of Science:

• Reproductive biology
• Spermatozoa processing
• Assisted reproductive technologies

Background:

• Sperm preparation is crucial for assisted reproduction.
• Effective methods are needed to isolate motile, viable spermatozoa.
• Evaluating sperm quality involves motility and hypoosmotic swelling (HOS) tests.

Purpose of the Study:

• To compare the efficacy of glass wool filtration and Percoll density gradient centrifugation for sperm selection.
• To assess the impact of these methods on sperm motility, HOS-reactivity, and acrosin activity.
• To determine the optimal method for different semen sample qualities.

Main Methods:

• Spermatozoa were processed using glass wool filtration and two-layer Percoll density gradient centrifugation.
• Recovery rates of progressively motile and HOS-positive spermatozoa were evaluated.
• Acrosin activity and percentage of normal sperm forms were assessed post-selection.
• Comparative analysis was performed on various semen sample types, including asthenozoospermic and frozen-thawed samples.

Main Results:

• Both methods yielded 50%–70% recovery of motile spermatozoa and 50% of HOS-positive spermatozoa.
• Glass wool filtration was more effective for asthenozoospermic samples and those with abnormal HOS tests.
• Acrosin activity increased two- to threefold post-selection, but normal sperm morphology did not improve significantly.
• Glass wool filtration demonstrated superior removal of non-motile and HOS-negative spermatozoa in samples with high proportions of these cells.

Conclusions:

• Glass wool filtration and Percoll centrifugation are simple, effective methods for selecting viable spermatozoa.
• Glass wool filtration offers advantages for specific sample types, particularly asthenozoospermic or poor-quality ejaculates.
• These techniques provide good recovery of motile spermatozoa and are preferable to more complex methods with lower yields.