It was introduced in 1910 by American biologists Samuel Cate Prescott and Robert Stanley Breed.
[1] It is a method for somatic cell count, to know the number of living and dead microorganisms.
The existing security in dairy products is given by the microbiological quality of the same, which ensures consumption from the point of view of health.
It is important first, to homogenize milk, heating it in a water bath at 40 °C for somatic cells that float to the surface along with the fat.
The laboratory apparatus must be clean but not necessarily sterile, since the method is based on cell count and asepsis is not accurate.
If later it is going to make detailed microbiological analyzes on the same sample, then it is necessary to be obtained and manipulated with sterile material.
For sampling there are two basic conditions to consider: The first one is to represent the total volume of milk from which it was removed, and the second condition involves to be stored and transported at the correct temperature so that they see their unmodified source properties, prior to analysis in the laboratory.
In case of delay in completion of the analysis a preservative that not alter the subsequent analytical result should be added to the milk.