Explain Direct Microscopic Count - Measurement of Microbes?

The most obvious way to determine microbial number is through direct counting under a microscope. In this method, a measured volume of the sample is placed within defined area on the microscopic slide and cells are counted under the microscope. In the breed count method for milk, 0.1 ml of the sample, is spread over a marked square centimeter area on a slide. Stain is added and the microbes are counted under a microscope for several different viewing fields. The average number of microbes/field can be calculated and used for calculating the number of microbes per square centimeter area or per 0.1 ml of the sample. Specially designed counting chambers like Petroff Hausser counting chamber, haemocytometer and electronic counter like coulter counter can also be used for direct measurement.