title: Single human sperm cryopreservation method using hollow-core agarose capsules.
abstract: OBJECTIVE
  To develop an efficient cryopreservation method using a single sperm.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  Laboratory of a private institute.
  
  
  METHODS
  A fertile donor.
  
  
  METHODS
  We produced hollow-core capsules with agarose walls. A single human sperm was injected into each capsule as per the conventional intracytoplasmic sperm injection (ICSI) method. The capsules that contained the spermatozoa were cryopreserved on polycarbonate or nylon mesh sheets using nitrogen vapor. Before their use, the capsules were thawed and recovered. The motile spermatozoa in the capsules were counted.
  
  
  METHODS
  The recovery rates of the agarose capsules and the spermatozoa in these capsules after thawing and the mortality and survival rates of the spermatozoa.
  
  
  RESULTS
  The recovery rates of the capsules were 91.5% (75/82) using polycarbonate sheets (PS) and 98.3% (59/60) using mesh sheets (MS) after thawing. The recovered capsules were not at all damaged. The recovery rates of the spermatozoa were 91.5% (75/82) using PS and 96.7% (58/60) using MS. Sperm motility rates were 85.3% (64/75) and 82.8% (48/58), whereas the survival rates of the immotile spermatozoa by the hypoosmotic swelling test were 81.8% (9/11) and 50.0% (5/10); furthermore, the total survival rates of the spermatozoa were 97.3% (73/75) and 91.4% (53/58) using PS and MS, respectively. There was no significant difference between the results obtained using PS and MS.
  
  
  CONCLUSIONS
  A cryopreservation method for a single sperm using an agarose capsule has been developed. The method is expected to be useful in ICSI treatment in patients with few spermatozoa.
authors.affiliation: The Institute for Assisted Reproductive Medical Technology, Fujimi, Maebashi, Gunma, Japan. Electronic address: yasuyuki@armt.net.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Araki
authors.affiliation: Fuso Pharmaceutical Industries, Ltd., Research and Development Center, Joto, Osaka, Japan.
authors.forename: Tatsuma
authors.initials: T
authors.lastname: Yao
authors.affiliation: Fuso Pharmaceutical Industries, Ltd., Research and Development Center, Joto, Osaka, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Asayama
authors.affiliation: Fuso Pharmaceutical Industries, Ltd., Research and Development Center, Joto, Osaka, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Matsuhisa
authors.affiliation: The Institute for Assisted Reproductive Medical Technology, Fujimi, Maebashi, Gunma, Japan.
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Araki
mesh_terms: D002214:Capsules / Q000737:chemistry; D002470:Cell Survival; D015925:Cryopreservation / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008297:Male; D008845:Microinjections; D012662:Semen Preservation / Q000295:instrumentation / Q000379:methods*; D012685:Sepharose / Q000737:chemistry; D020554:Sperm Injections, Intracytoplasmic; D013094:Spermatozoa / Q000166:cytology
chemical_list: D002214:Capsules; D012685:Sepharose
keywords: Agarose capsule; a single human sperm; cryopreservation; nylon mesh sheets; polycarbonate sheets