Microbial growth measurement Microbial growth (increase in the number of cells formed as a result of division) can be estimated in several ways: 1.You can follow one of the following methods: A- Estimation of the total number of cells: This count is done directly under the microscope in colored preparations.A known volume of the microbial culture or suspension (0.01 ml) is spread evenly over a known area of a glass slide The resulting membrane is fixed and colored, then the individual microbes are counted by examining it under the microscope field.The number of cells in (1 ml) of the suspension is calculated.- Estimation of the total number of cells cont., o Special plates (as Petroff hausser, hemocytometer) are used, which have a counting chamber that helps to carry out the count accurately and quickly without coloring.or indirectly depending on the degree of medium turbidity.2.3.