Modification of the Wang tube to improve in vitro semen manipulation.

The Wang tube was modified to improve in vitro semen manipulation, by adding another two racks to the anterior (posterior) wall of the low component of the Wang tube and supplying another four convex lenses symmetrical to those on the bottom wall. The former provides a slanted position leading to a complete real-time sperm separation image and benefiting low-quality sperm preparation when the modified Wang tube is turned on its side. The latter converses the microscope's light better and gives a clearer objective image.