A process and system for selecting mature sperm for assisted reproduction techniques such as intracytoplasmic sperm injection comprises applying a binding substrate specific to mature sperm to a surface; applying a sperm suspension to the surface; and contacting the sperm suspension and the mature sperm binding substrate on the surface. The process then comprises permitting mature sperm from the sperm suspension to bind to the mature sperm binding substrate at a periphery thereof; and removing bound sperm from the periphery of the mature sperm binding substrate. Preferably, the mature sperm binding substrate is a fluid and comprises hyaluronic acid or a salt thereof, a polysaccharide, a glycosaminoglycan, a zona pellucida component, zona protein of the egg membrane or a structural or functional homolog or analog of the sperm-binding elements of the female reproductive tract or the zona pellucida, a proteoglycan, or an antibody to a protein receptor for mature sperm.
