Cryopreserved selected sperm cell sample

Abstract

The present invention provides a method of cryopreserving sperm that have been selected for a specific characteristic. In a preferred embodiment, the method is employed to freeze sex-selected sperm. Although the cryopreservation method of the invention can be used to freeze sperm selected by any number of selection methods, selection using flow cytometry is preferred. The present invention also provides a frozen sperm sample that has been selected for a particular characteristic, such as sex-type. In preferred embodiments, the frozen sperm sample includes mammalian sperm, such as, for example, human, bovine, equine, porcine, ovine, elk, or bison sperm. The frozen selected sperm sample can be used in a variety of applications. In particular, the sample can be thawed and used for fertilization. Accordingly, the invention also includes a method of using the frozen selected sperm sample for artificial insemination or in vitro fertilization.

1 . A frozen selected sperm sample comprising a portion of the sperm present in a source sample, said portion of sperm selected for a characteristic. 
     
     
         2 . The frozen selected sperm sample of  claim 1 , wherein said frozen selected sperm sample comprises sex-selected sperm. 
     
     
         3 . The frozen selected sperm sample of  claim 1 , wherein said frozen selected sperm sample comprises mammalian sperm. 
     
     
         4 . The frozen selected sperm sample of  claim 1 , wherein said frozen selected sperm sample is produced by a method comprising: (a) obtaining a selected sperm sample, said selected sperm sample containing a sufficient number of selected sperm cells to fertilize an egg of a non-human mammal; and (b) freezing said selected sperm. 
     
     
         5 . The frozen selected sperm sample of  claim 4 , wherein said frozen selected sperm sample is produced by the method further comprising the step of adding an extender to said selected sperm sample. 
     
     
         6 . The frozen selected sperm sample of  claim 5 , wherein said extender comprises a final extender added to said selected sperm sample prior to said freezing step, said final extender including at least one cryoprotectant. 
     
     
         7 . The frozen selected sperm sample of  claim 4 , wherein said frozen selected sperm sample is produced by the method further comprising the step of isolating selected sperm from said selected sperm sample to produce isolated sperm. 
     
     
         8 . The frozen selected sperm sample of  claim 7 , wherein said extender comprises an initial extender added to said selected sperm sample. 
     
     
         9 . The frozen selected sperm sample of  claim 8 , wherein said initial extender includes a component that maintains osmolality and buffers pH. 
     
     
         10 . The frozen selected sperm sample of  claim 9 , wherein said initial extender further includes an organic substance that reduces cold shock and preserves fertility of sperm. 
     
     
         11 . The frozen selected sperm sample of  claim 9 , wherein said initial extender further includes an energy source. 
     
     
         12 . The frozen selected sperm sample of  claim 9 , wherein said initial extender further includes an antibiotic. 
     
     
         13 . The frozen selected sperm sample of  claim 9 , wherein a flow cytometer selects said sperm, and wherein a sheath fluid flowed in said flow cytometer comprises said initial extender. 
     
     
         14 . The frozen selected sperm sample of  claim 8 , wherein said initial extender further includes at least one cryoprotectant, said initial extender including said at least one cryoprotectant added after the step of isolating selected sperm as a final extender. 
     
     
         15 . The frozen selected sperm sample of  claim 14 , wherein said frozen selected sperm sample is produced by the method further comprising the step of cooling said selected sperm sample. 
     
     
         16 . The frozen selected sperm sample of  claim 15 , wherein said frozen selected sperm sample is produced by the method further comprising the step of cooling said selected sperm sample between about 4° Celsius and about 5° Celsius. 
     
     
         17 . The frozen selected sperm sample of  claim 16 , wherein said frozen selected sperm sample is produced by the method further comprising the step of cooling over a period of about 60 minutes to about 240 minutes. 
     
     
         18 . A method comprising using the frozen selected sperm sample of  claim 1  for artificial insemination. 
     
     
         19 . A method comprising using the frozen selected sperm sample of  claim 1  for in vitro fertilization.