Thermal convection counter streaming sedimentation and forced convection galvanization method for controlling the sex of mammalian offspring
First Claim
1. A method of separating sperm cells of differing densities and electrical potentials from semen comprising the steps of:
- mixing semen with a liquid suspending medium;
immobilizing the sperm by cooling the mixture;
applying both positive and negative buoyant forces to the sperm whereby more dense sperm attain a different level in the liquid medium than less dense sperm;
applying galvanic force to .Iadd.a portion of .Iaddend.said medium .Iadd.containing an unbalanced sperm population as a result of the preceding step .Iaddend.while circulating said medium by convection so as to separate sperm having different net electrical cell surface potentials; and
withdrawing a fraction of the medium containing the desired sperm.
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Accused Products
Abstract
A method and apparatus for controlling the sex of mammalian offspring by separation of the X-chromosome female producing sperm and Y-chromosome male producing sperm according to their different characteristics of density of the respective cells and electric potential on the respective cell surfaces. Separation is accomplished by first producing at thermal convection counter stream within a sedimentation column containing a universal medium with sperm suspended therein and allowing the two sperm populations to settle into different fractions according to different densities. Subsequently, the fractions are further separated and concentrated utilizing convection galvanization. The positive and negative geotaxis applied to the sperm during thermal convection sedimentation in combination with galvanic forces applied during the convection galvanization facilitate a more efficient separation than previously obtained. This is due to the fact that a greater degree of separation of X and Y sperm is achieved by subjecting an unbalanced population of sperm cells, i.e., one predominating in X or Y cells, to convection galvanization. Thermal convection counter streaming sedimentation has been found to be a preferred method for attaining this unbalanced sperm population. The apparatus used to accomplish the above separation includes means for producing a temperature differential between axial and peripheral portions of the medium contained in the sedimentation column, thus creating the necessary thermal convection counter stream, as well as an electrophoreses cell comprising a convection column disposed between the two electrodes of the cell. Alternatively, the sedimentation apparatus and the convection galvanization apparatus may be combined. Additionally, the apparatus may comprise a laser capable of scanning the length of the thermal convection sedimentation column as well as laser detecting means to determine the distribution of sperm produced within the medium therein.
40 Citations
21 Claims
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1. A method of separating sperm cells of differing densities and electrical potentials from semen comprising the steps of:
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mixing semen with a liquid suspending medium; immobilizing the sperm by cooling the mixture; applying both positive and negative buoyant forces to the sperm whereby more dense sperm attain a different level in the liquid medium than less dense sperm; applying galvanic force to .Iadd.a portion of .Iaddend.said medium .Iadd.containing an unbalanced sperm population as a result of the preceding step .Iaddend.while circulating said medium by convection so as to separate sperm having different net electrical cell surface potentials; and withdrawing a fraction of the medium containing the desired sperm. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of separating mammalian sperm according to phenotypical differences related to normal and abnormal genotypes comprising the steps of:
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mixing fresh semen with a liquid suspending medium; separating the mixture by thermal convection counter streaming sedimentation according to different sperm densities into three fractions, a first fraction containing predominantely X-sperm of a normal genotype, a second fraction containing predominately Y-sperm of a normal genotype, and a third fraction containing both X and Y-sperm carrying defective genes; and subjecting a desired fraction of said medium to convection galvanization thus further separating and concentrating all X-sperm of a normal genotype and all Y-sperm of normal genotype. - View Dependent Claims (14, 15)
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16. A method of separating sperm cells of differing cell surface electrical potentials from semen comprising the steps of:
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mixing the semen with a liquid suspending medium; applying galvanic force to said medium while subjecting it to convection circulation whereby sperm of one net cell surface electrical potential attain a different position within said medium than sperm of a differing net cell surface electrical potential; and withdrawing a fraction of the medium containing the desired sperm type. - View Dependent Claims (17, 18, 19, 20)
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21. A method of controlling the sex of mammalian offspring comprising the steps of:
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mixing fresh sperm with a liquid suspending medium; subjecting said mixture to thermal convection counter streaming sedimentation to separate according to differing densities sperm having X-chromosomes from sperm having Y-chromosomes; removing a desired fraction of said mixture from said sedimentation column; subjecting the desired fraction of said mixture to forced convection galvanization to further separate and concentrate according to different cell electrical potentials substantially all sperm having X-chromosomes from all sperm having Y-chromosomes; and introducing the desired fraction into a female whereby conception occurs and offspring of the desired sex are produced.
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Specification