The sex of an animal can have large economic implications on a large producing farm. One example is an egg farm where the male sex does not contribute to production therefore half the offspring is undesirable. The ability to control sex can have great benefits to genetic progress and herd management. The objective of this study was to test new methods for identification sex specific markers on the sperm surface which can be used to develop new sperm sexing technology. The researchers used aptamers to help detect slight molecular signatures within biological systems. A procedure was developed to select two aptamer families, X- and Y. The X- and Y-aptamer families were found to have increased binding to X- and Y-sorted sperm. Current results have shown that binding of a X-aptamer might be sex-specific but more tests will have to be done to make sure. If the specific X-aptamer was found to be sex-specific it would be the first confirmed presence of a sex-specific membrane marker on mammalian sperm. This would have large scientific implications as well as commercial benefits to herd management.