The Makler Counting Chamber is only 10 microns deep: 1/10th of the depth of ordinary hemocytometers, making it the shallowest of known chambers. Constructed from two pieces of optically flat glass, the upper layer serves as a cover glass, with a 1 sq.mm fine grid in the center subdivided into 100 squares of 0.1 x 0.1 mm each. Spacing is firmly secured by four quartz pins. A small, uncalibrated drop from a well mixed undiluted specimen is placed in the center of the Chamber by means of a simple rod and immediately covered. A microscopic objective of x20 is required. Non-motile sperm are counted within an area of nine or sixteen squares in the center of the grid. Moving sperms are then counted, and graded if desired. The procedure is repeated in several areas. Percentage of motility and its quality are then calculated. A part of the original specimen is transferred to another test tube for immobilization by placing the tube in hot water (50o-60o): a cup with 2/3 boiling water and 1/3 tap water is suggested. A drop of the immobilized specimen is then placed in the Chamber and counting initiated: sperm heads within a ten square area are counted in the same manner as blood cells are counted in a hemocytomer, their number represents their concentration in millions per ml. In cases of oligospermic semen, sperms in the entire grid area are to be counted, representing their concentration in hundreds of thousands. For more information, visit ZDL Global.