Membrane filters are popular for their porosity that is around 0.45um. This standard pore size is enough to filter out small microorganisms from a liquid sample. Using a membrane filter works by passing the sample through a membrane while utilizing a filter and a vacuum system. The filtered organisms are stuck to the membrane and it is then either disposed or put in a plate with the applicable medium.


Today, the technique that utilizes membrane filters has been accepted as an efficient and effective method of sample testing for contaminations. It is preferred by many researchers because it involves lesser steps in the preparation phase compared to other traditional methods. It is also one of the few ways that isolate microorganisms rather than killing them.


The Procedure


The whole process of a membrane filter technique is easy so many researchers prefer it because it is much faster compared to other methods. Here is a condensed step-by-step guide on how to perform this technique:


  • Gather the necessary sample. Make sure you have done the appropriate dilutions.

  • Attach the membrane filter in a pre-prepared funnel assembly.

  • Turn the vacuum one to let the sample completely draw through the membrane filter.

  • Remove the membrane filter and place it in a Petri dish.

  • Incubate it under the right temperature and the right duration.

  • Confirm the colony count and generate a report of the results.


The Benefits of the Membrane Filter Technique


Aside from the simplicity of the process, there are also many benefits that a research laboratory will get from this technique.


  • This technique enables the testing of samples in large volumes. In theory, all non-turbid water can be accommodated with this technique.

  • The membrane filter used in the process can also be easily relocated from one type of medium to another with the intention of differentiation and selection of organisms. This results in the enumeration and isolation of bacteria colonies.

  • There is a faster turnaround of the results compared to the standard methods. The results could be gathered in as short as 24 hours.



Membrane Filter Uses


There are a lot of situations where the use of membrane filters is considered vital and important. First, they are very popular in laboratories and in industries that involve sterilization. This is because this technique saves a lot of their time and they can proceed with the core processes faster.


Second, the membrane filter technique is also accepted and actually deemed effective when it comes to monitoring drinking water. This is especially helpful in locations where the cleanliness of water must be closely monitored.


Lastly, this technique is very useful when it comes to the monitoring of the presence of bacteria in many industries such as cosmetics, pharmaceutics, electronics, and even in the industry of food and beverage. The only thing that you need to remember when you want to use the membrane filter technique is to ensure that you do your research on the appropriate membrane filter to use. You should first educate yourself about membrane filters before you dive in to do this technique so that you can arrive at better results.