Microbiological Water Quality Determination:
The methods to estimate the microbiological quality of water are:
(a) Membrane Filter (MF) technique
(b) Standard Plate Count Test (SPT)
(c) Most Probable Number (MPN)
Membrane Filter (MF) Technique
This method determines and measures presence of coliform bacteria. In this method, 10 ml sample water is filtered through a sterile membrane of special type having porosity of 80%. On this membrane, the bacteria are retained if present. After filtration the membrane is put in contact with nutrients (M-Endo's medium) at 35oC for 24 hours that permits growth of only coliform colonies. The coliform organisms are developed into visible colonies, which are counted.