Filtration refers to an interesting sterilization method in laboratories. It is the only method that uses force to separate rather than killing. When you filter a gas or liquid, it passes through a pore, which filters out or stops the passage of larger particles.
Filtration of liquids depends on the sizes of pores, the smaller the pores, the more particles will be screened out.
In this article, we shall focus on the filtration process, how it works, the pros and cons of the process among others.
Filtration definition and how does it work
Filtration is distinct from other sterilization methods that are out there. It is defined as a process that removes or deactivates all forms of biological agents. All the sterilization methods covered kill or deactivate the viruses and bacteria.
Filtration eliminates bacteria by detaching the microorganisms from the sterilized medium. It works in a very simple way. You are familiar with water filters found at home, office or a coffee percolator which use the same mechanism of filtration.
Filtration uses membranous filters which has tiny pores.
Filtration of Liquids in the Lab
Liquids are filtered through microbial filters to get rid of any microbes in the lab. It is a productive method of sterilization for heat sensitive liquids. The four types of filters include:
- Membrane filters -they are made of cellulose. It is during injection by placing the membrane between the needle and syringe.
- Seitz filters –they are made of asbestos. They are thicker and pad-like than membrane filters.
- Sintered glass filters- they are made of glass hence does not absorb liquids during filtration.
- Candle filters– they are made of clay-like mud. The special mud has tiny pores that are made by algae.
There are several filtration techniques. Home filtration systems are used by Reverse Osmosis. Other common methods are, micro-filtration, nano-filtration, ultra-filtration and particle filtration.
It is essential to know that are various techniques and each technique is well-suited for a specific application.
Advantages of Filtration
Some of the notable advantages of the filtration process include;
- It is relatively cheap apart from for those with the smallest pore sizes
- The filters do not clog easily
- It is suitable for heat sensitive liquids as filters do not use any heat
- They usually filter large volumes of fluid in a fast rate
Disadvantages of Filtration
The demerits of filtration are as follows;
- Filters can will only work on gases and liquids
- Autoclaving is cheaper than filtration. It is because filters are expensive to replace, especially the nano-filters
- Glass filters can be easy to break and brickle
- Membrane filters usually rupture easily
- The solution in Sietz Filters usually gets absorbed by the filter pad itself
- Clogging usually occurs
- It is a long and tedious process
There are various types of filtration that can be used in the lab. It is a physical method which separates microbes such as bacteria found in liquids. With this information in handy, you will know which filtration method to use in the lab.