Water Quality Analysis by Most Probable Number (MPN)

Water Quality Analysis by Most Probable Number (MPN)

The most probable number (MPN) analysis is a statistical method based on the random dispersion of microorganisms per volume in a given sample. In this method, measured volumes of water are added to a series of tubes containing a liquid indicator growth medium. The media receiving one or more indicator bacteria show growth and a characteristic color change. The color change is absent in those receiving only an inoculum of water without indicator bacteria. From the number and distribution of … Read more

Water Quality Analysis by Membrane Filter (MF) Technique

Membrane Filter (MF) Technique

The Membrane Filter (MF) Technique was introduced in the late 1950s as an alternative to the Most Probable Number (MPN) procedure for microbiological analysis of water samples. It involves the use of membrane filters, which are thin porous sheet structures composed of cellulose esters or similar polymeric materials. They act essentially as two-dimensional screens and as such, all particles, both biological and non-biological, which exceed the pore size, are retained upon the surface of the filter from fluids passing through. … Read more