OBJECTIVES: To develop a new method for the long-term preservation of human sperm. SETTING: Andrology laboratory of our hospital. PATIENTS: Thirty-one normal and 19 asthenozoospermic semen samples obtained from patients attending our infertility clinic. The average sperm motility was 70.2% and 36.0% in the normal and asthenozoospermic groups, respectively. INTERVENTIONS: Ejaculated sperm were centrifuged and washed using the electrolyte-free Percoll gradient and then were preserved at 4 degrees C. MAIN OUTCOME MEASURES: The motility of the preserved sperm was analyzed using computer-assisted semen analyzer after the addition of Ham's modified F-10 (GIBCO, Grand Island, NY). RESULTS: In the normal group, motility rate after the addition of Ham's F-10 for 1, 2, and 4 weeks of preservation was 65.4%, 40.4%, and 5.5%, respectively. In the asthenozoospermic group, motility rate after 1 and 2 weeks of preservation was 31.3% and 18.1%, respectively. Preservation solutions containing sodium or potassium decreased motility after preservation. Restoration of preserved sperm was not achieved by incubation alone; however, reinitiation was induced by incubation together with Ham's F-10. CONCLUSIONS: Human sperm in the electrolyte-free solution survived for a long period of time at 4 degrees C and reinitiation of sperm motility after preservation required the addition of Ham's F-10.
OBJECTIVES: To develop a new method for the long-term preservation of human sperm. SETTING: Andrology laboratory of our hospital. PATIENTS: Thirty-one normal and 19 asthenozoospermic semen samples obtained from patients attending our infertility clinic. The average sperm motility was 70.2% and 36.0% in the normal and asthenozoospermic groups, respectively. INTERVENTIONS: Ejaculated sperm were centrifuged and washed using the electrolyte-free Percoll gradient and then were preserved at 4 degrees C. MAIN OUTCOME MEASURES: The motility of the preserved sperm was analyzed using computer-assisted semen analyzer after the addition of Ham's modified F-10 (GIBCO, Grand Island, NY). RESULTS: In the normal group, motility rate after the addition of Ham's F-10 for 1, 2, and 4 weeks of preservation was 65.4%, 40.4%, and 5.5%, respectively. In the asthenozoospermic group, motility rate after 1 and 2 weeks of preservation was 31.3% and 18.1%, respectively. Preservation solutions containing sodium or potassium decreased motility after preservation. Restoration of preserved sperm was not achieved by incubation alone; however, reinitiation was induced by incubation together with Ham's F-10. CONCLUSIONS:Human sperm in the electrolyte-free solution survived for a long period of time at 4 degrees C and reinitiation of sperm motility after preservation required the addition of Ham's F-10.