The DHCS consists of 100 small squares in the large center square. Each small square measures 0.1 x 0.1 mm, with a chamber depth of 0.02 mm. Each small square has a total volume of 2.0 x 10^{4}mm^{3} or 2.0 x 10^{7}cm^{3}.
Count all the cells in the 100 small squares within the large center square. The large center square has a surface area of 1.0 mm^{2} and a chamber depth of 0.02 mm. The large center square has 0.02 mm^{3}. As there are 1000mm^{3} per ml, the center square represents a volume of 0.00002ml, so that equates to 1/ 0.0002ml = 50,000 (50,000 = 1/ (100 squares x 2.0 x 10^{7}cm^{3}). The volume factor is then 50,000.
