Apparatus and method for separating motile sperm

A device for sorting motile from non-motile sperm comprising upper and lower tubes, the lower tube closed at one end and the upper tube having a mesh at its lower end and fitting into the lower tube such that when the tubes are assembled a passage is formed between a narrow part of the external wall of the upper tube and an internal wall of the lower tube. Semen is placed on the mesh of the upper tube and medium placed on the semen ensuring they are not mixed and the tubes placed in an incubator. Non-motile sperm, cells, debris and seminal plasmsa flows from the upper tube into the lower tube via the mesh pores and at the same time air flows out of the lower tube through the passage between the tubes. Active, motile sperm separate by swimming upstream into the upper tube and remain in the medium.