title: Simultaneous swim-up/swim-down of sperm in assisted reproduction procedures.
abstract: OBJECTIVE
  High-quality motile human spermatozoa were obtained following treatment of semen by simultaneous swim-up into medium and swim-down into an isotonic 40% Percoll solution.
  
  
  RESULTS
  This procedure was significantly better than the swim-up method and comparable to discontinuous Percoll gradient centrifugation. Recovery rates of motile sperm were 35% for swim-up, 65% for Percoll gradient centrifugation, and 73% for swim-up/swim-down.
  
  
  CONCLUSIONS
  The swim-down sperm was inferior to the swim-up sperm in its upward migration capacity but superior in morphology. Spermatozoa obtained by the swim-up/swim-down procedure demonstrated fertilizing ability in IVF, and clinical pregnancies were established. The simultaneous swim-up/swim-down procedure offers an alternative efficient method of simple separation of high-quality motile sperm for various assisted reproduction techniques.
authors.affiliation: Department of Obstetrics & Gynecology, Bikur Cholim Hospital, Jerusalem, Israel.
authors.forename: M
authors.initials: M
authors.lastname: Almagor
authors.forename: D
authors.initials: D
authors.lastname: Benbenishti
authors.forename: D
authors.initials: D
authors.lastname: Rosenak
authors.forename: Y
authors.initials: Y
authors.lastname: Mogle
authors.forename: H
authors.initials: H
authors.lastname: Yaffe
mesh_terms: D002469:Cell Separation / Q000379:methods*; D002499:Centrifugation, Density Gradient; D003102:Colloids; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007315:Insemination, Artificial; D008297:Male; D011205:Povidone; D011247:Pregnancy; D012822:Silicon Dioxide; D013081:Sperm Motility / Q000502:physiology*; D016896:Treatment Outcome
chemical_list: D003102:Colloids; C016039:Percoll; D012822:Silicon Dioxide; D011205:Povidone