Methods for sorting sperm and producing sexed embryos

Abstract

A method of sorting sperm cells and a method of producing at least one sexed embryo. The method of sorting sperm cells includes the steps of establishing a sheath fluid environment including a citrate for stained sperm cells, establishing a stream including stained sperm cells in said sheath fluid environment, sensing a property of the stained sperm cells, and discriminating between stained sperm cells for a desired sex characteristic. The method of producing at least one sexed embryo includes the steps for sorting sperm cells in addition to fertilizing at least one egg with the sexed sperm to form at least one sexed embryo.

We claim: 
     
         1 . A method of sorting sperm cells comprising:
 establishing a sheath fluid environment for stained sperm cells, the sheath fluid environment including a citrate;   establishing a stream comprising said stained sperm cells in said sheath fluid environment;   sensing a property of the stained sperm cells; and   discriminating between stained sperm cells for a desired sex characteristic.   
     
     
         2 . The method of  claim 1 , wherein the step of discriminating between stained sperm cells for a desired sex characteristic comprises the step of differentiating X chromosome bearing sperm cells from Y chromosome bearing sperm cells. 
     
     
         3 . The method of  claim 1 , wherein changes in the amount of citrate are minimized between the sheath fluid environment and a pre-sort and/or a post-sort fluid environments. 
     
     
         4 . The method of  claim 1 , further comprising:
 forming drops from the stream containing the sperm cells;   charging drops having sperm cells with the desired sex characteristic; and   collecting drops having sperm cells with the desired sex characteristic.   
     
     
         5 . The method of  claim 4 , wherein the step of collecting drops having sperm cells with the desired characteristic further comprises: collecting drops having sperm cells with the desired characteristic in a wide collection tube. 
     
     
         6 . The method of  claim 4 , wherein the step of collecting drops having sperm cells with the desired characteristic further comprises: collecting drops having sperm cells with the desired characteristic in a stream matched collection tube. 
     
     
         7 . A method of producing a sexed sperm specimen according to the process of  claim 1 . 
     
     
         8 . The method of  claim 7 , further comprising preparing an artificial insemination dosage having less than one half of the typical number of sperm provided in a typical artificial insemination dosage. 
     
     
         9 . A method of sorting sperm cells comprising:
 chemically coordinating a sheath fluid environment for stained sperm cells with a pre-sort fluid environment or post-sort fluid environment;   supplying stained sperm cells in a stream comprising said chemically coordinated;   sensing a property of said stained sperm cells; and   discriminating between stained sperm cells having a desired sex characteristic.   
     
     
         10 . The method of  claim 9 , wherein the step of chemically coordinating a sheath fluid environment with a pre-sort environment or a post-sort fluid environment further comprises incorporating a citrate into the sheath fluid. 
     
     
         11 . The method of  claim 10 , wherein changes in the amount of citrate are minimized between the sheath fluid environment and a pre-sort and/or a post-sort fluid environments. 
     
     
         12 . The method of  claim 10 , wherein the step of chemically coordinating a sheath fluid environment with a pre-sort environment or a post-sort fluid environment further comprises incorporating comprises a chemical in the citric acid cycle into the sheath fluid. 
     
     
         13 . The method of  claim 9 , further comprising:
 forming drops from the stream containing the sperm cells;   charging drops having sperm cells with the desired sex characteristic; and   collecting drops having sperm cells with the desired sex characteristic.   
     
     
         14 . The method of  claim 13 , wherein the step of collecting drops having sperm cells with the desired characteristic further comprises: collecting drops having sperm cells with the desired characteristic in a wide collection tube. 
     
     
         15 . The method of  claim 13 , wherein the step of collecting drops having sperm cells with the desired characteristic further comprises: collecting drops having sperm cells with the desired characteristic in a stream matched collection tube. 
     
     
         16 . A method of producing a sexed sperm specimen according to the process of  claim 1 . 
     
     
         17 . The method of  claim 16 , further comprising preparing an artificial insemination dosage having less than one half of the typical number of sperm provided in a typical artificial insemination dosage. 
     
     
         18 . A method of producing at least one sexed embryo comprising:
 establishing a sheath fluid environment for stained sperm cells, the sheath fluid environment including a citrate;   establishing a stream comprising said stained sperm cells in said sheath fluid environment;   sensing a property of the stained sperm cells;   discriminating between stained sperm cells having a desired sex characteristic;   and fertilizing at least one egg with the sexed sperm to form at least one sexed embryo.   
     
     
         19 . The method of  claim 18 , wherein the at least one egg is fertilized in vitro with the sex selected sperm. 
     
     
         20 . The method of  claim 18 , wherein the step of fertilized in vivo further comprises the step of delivering sperm cells into both uterine horns of a uterus.