To many researchers, filtration might just be the most interesting method used for sterilization in their laboratories. Out of all the methods, it is the only one that foregoes the killing of organisms and instead, adopts the process of using force in order to separate unnecessary particles and organisms from the sample. This is why a sterile syringe filter exists.




















Filtration can be done on many levels. Oftentimes, this depends on the filter’s pore size. Read on to know more about this process.

How It Works?


In Wikipedia, sterilization is defined as a method to eliminate or kill every single life form present in a particular sample. However, filtration works in a very different way. In filtration, the life forms are being eliminated from the sample by separating them. Its operating concept is actually so simple to understand.


Think of the water filter you have at home. It has layers of filters that can trap large particles from contaminating the water flowing through it. Similarly, the filtration method in laboratories follows the same mechanism.


This method utilizes a filter that is membranous containing very little pores that can allow liquid to pass through but block the larger particles like bacteria. So logically, if the filter has smaller pores, the more particles it can block, including tiny life forms.


Filter Types


There are mainly four types of filters that are commonly used in laboratories.


Seitz filters: They are created from asbestos. They resemble more like a pad and they are thicker compared to the normal membrane filters.


Membrane filters: These filters are thin and they are created from cellulose. They are commonly used with injection as they can be placed in between the needle and the syringe.


Sintered glass filters: They are obviously made of glass. So, they are perfect for filtering gasses as the liquid will be unable to penetrate through glass.


Candle filters: These filters use clay mud. The mud consists of little pores that are created by algae. The tiny life forms stick to the pores when the liquid is traveling through.


Filtration Techniques


As we have introduced above, filtration can be done on many levels. The most common one is reverse osmosis, which is a technique widely used in many filtration systems at home. Other techniques include nano-filtration, micro-filtration, ultra-filtration, and the particle filtration. They all basically have the same mechanism. The only difference is the pore size of the filter used in each of the techniques.


Benefits and Drawbacks of Filtration


There are clearly a lot of advantages when doing the filtration method. It includes the following ones:


  • They are affordable. But, remember that the smaller the pore size gets, the more expensive the filters are.
  • Filters are made to not clog that easily.
  • They are perfect for those that have to work with liquids that are sensitive to heat.
  • They can work with big volumes of liquid efficiently.


However, there are also a few disadvantages too.


  • Their use is only limited to gasses and liquids.
  • When not handled correctly, membrane filters can easily rupture.
  • There is a long process that you need to follow when you use a sterile syringe filter, but it is worth it in the end.