MicroSort is a sperm separation method based on the difference in the amount of genetic material in sperm. Sperm carrying an X chromosome have approximately 2.8% more DNA material than sperm carrying a Y chromosome.
During the MicroSort process the sperm sample is washed to remove seminal liquid and nonmotile cells. After the washing, the sample is stained with a special fluorescent material that attaches to the DNA contained in the sperm.
The stained sperm are analyzed one by one by a flow cytometer, where cells pass through a laser which makes the stain attached to the DNA fluoresce. The sperm containing the X chromosome (which have more DNA and therefore more stain) will shine brighter than the sperm containing the Y chromosome.
The flow cytometer uses special software to identify X and Y chromosome sperm based on their fluorescence signature. The sperm carrying the chromosome that will produce the desired gender are separated from the rest of the sample, resulting in an enriched sperm sample ready for use.
The sorting process of each semen sample takes between six and seven hours, and many assisted reproductive techniques allow MicroSort to cryopreserve the samples for future use, or shipment to any part of the world.