Microbial Analysis of Water

Water is the source of all life, even microscopic ones. For this reason, testing for microscopic organisms in water is important to meet human standards. The World Heath Organization provides several techniques in testing microbes, either through conventional or rapid analysis.

Filtration Technique

• Filtration is a conventional method to grow microbial communities. The sample is filtered through a small pour-size membrane filter. The membrane filter is then warmed, or inoculated, and given a type of broth to spur the growth of microbes. After a few days, the microbes grown are counted.

Immunocapture Method

• According to the World Health Organization, the immunocapture method is a technique that uses magnetic beads coated in antibodies to attract microbes in a water sample. This type of rapid detection analysis can determine if virus and bacterias are present in a water sample in only a few hours.

Flocculation Method

• This conventional method is very successful in counting and detecting microbes by attracting negative charged viruses to a positive-charged surface. Opposite charges attract causing viruses to flocculate, or clump together. After flocculation, the sample is centrifuged and filtered for counting.

Cultivation

• Cultivation techniques generally use petri dishes or test tubes to grow different types of microscopic organisms. This conventional method requires the sample to be diluted and placed on a type of growing media in a petri dish or culture tube. These dishes or tubes are then warmed, or inoculated, to spur the growth of organisms. After a few days, they are then counted.

Visualization Methods

• These methods are very rapid in determining types and amounts of microbial communities. By using a light beam and a reagent, the concentration of microbes react with the reagent, causing a color change. The light beam is scattered through the sample and measured instantaneously.