MicroSort^® Technology

Background
The sex of a child is determined by the specific sperm cell fertilizing the egg at the time of conception (view sperm cells). Sperm cells carrying an X chromosome result in a female and those carrying a Y chromosome result in a male. Semen contains approximately 50% female and 50% male sperm cells. Any system designed to separate X- (female) and Y- (male) sperm cells must have (1) the ability to identify and measure a difference between female and male sperm cells, (2) separate the cells based on the measurable difference, and (3) directly determine the results of the separation process.

Scientific Basis
The MicroSort technology is based on the fact that the X chromosome is substantially larger than the Y chromosome (view X&Y chromosome). Since chromosomes are made of DNA, human sperm cells having an X chromosome will contain approximately 2.8% more total DNA than sperm cells having a Y chromosome . This DNA difference can be measured and the X- and Y-bearing sperm cells individually separated using a modified flow cytometer instrument (view representative instrument). The resulting purity (enrichment) of the separated sperm cells can be determined by a DNA analysis method called FISH (fluorescence in situ hybridization) in a small unused portion of the sorted sample. FISH uses DNA probes that specifically attach to either the X or Y chromosome in sperm and emit a red/pink color for X-bearing sperm and green for Y-bearing sperm. The X- and Y-bearing sperm can be identified and counted under a microscope to determine the purity (view FISH analysis).

Technology Development
The flow cytometric sperm separation technology was originally developed in animals by Dr. Lawrence Johnson at the United States Department of Agriculture (USDA). The Genetics & IVF Institute (GIVF) in collaboration with Dr. Johnson further developed the technology for use in humans.

Clinical Trial
Based on the birth of over 400 normal healthy offspring from four animal species including 3 successive generations in swine and 5 successive generations in rabbits, GIVF established an Institutional Review Board (IRB) approved clinical trial study for use of the MicroSort technology in humans.