The full grid on a hemocytometer contains 9 squares, each of which is 1 mm square. Large cells are counted using the four large corner squares (and the middle one). If you use a dense suspension of small cells, the four 1/25 sq. mm corners plus the middle square in the central square are used. The grid consists of 9 large squares, each measuring 1 x 1 mm, and a chamber depth of 0.1 mm. Each square has a total volume of 0.1 mm3 or 10-4cm3. The central square is divided into 25 small squares with triple lines and four corner squares are divided into 16 small squares. Each large square has a surface area of 1.0mm2, and the depth of the chamber is 0.1mm. As there are 1000 mm3 per ml, each large square represents a volume of 0.0001ml, so that it is equal to 1/ 0.0001ml = 10,000 = (104) |