Laminar flow cabinet: an important piece of equipment for a lab
If you have ever visited a plant tissue culture (PTC) lab, or have the intention to open your own PTC lab, then maybe you have asked yourself the question :
Which equipment do I need first for my PTC lab?
For a functioning plant tissue culture lab, sterility is the most important part. And there are certain equipment required for this purpose.
Among all the equipment we need for maintaining sterility, let us today talk about laminar flow cabinets!
For efficient plant tissue culture practice, we should have one or more laminar flow cabinets in a laboratory. These cabinets are popular for their use in contamination-sensitive processes such as molecular experiments, plant tissue culture, etc. . Some researchers get their flow cabinets tailor-made for some specialized works. These cabinets are also available for general lab techniques for microbiological and industrial sectors. However, keeping plant tissue culture in mind, it is interesting to know that these cabinets are useful for performing different steps during tissue culture. They keep the working surface sterile not only during inoculation but also during subculture, transfer for multiplication, and even rooting.
If you are new to the exciting world of plant tissue culture, it might be interesting for you to read on different aspects of a tissue culture laboratory in our blog on "How to set up a tissue culture laboratory?". In this article you can also find out about the different equipment you need for performing tissue culture experiments!
Why laminar flow cabinets?
Laminar flow cabinets help in creating a particle-free working environment by projecting air through a filtration system.
Interesting isn't it?
In simple terms, there are millions of particles floating in the ambient air. They may comprise of microbes such as viruses, bacteria, fungi and many more. These are not suitable for plant tissue culture! Eventually, these floating particles will land on objects such as culture vessels, explants, etc. and cause contaminations. For this very reason, it is necessary for you to ensure clean and sterile air flowing over your tools, containers and specimens. In order to achieve this goal, you need a proper air treatment equipment such as laminar flow cabinets. Hence, they are a must-have for any plant tissue culture laboratory as working sterile is the key to a successful culture.
How does a laminar flow hood work?
Before we go into details of the working principle, let us first understand one important component of a laminar flow cabinet: the HEPA filter! It abbreviates as 'high-efficiency particulate air filter'. It is present within the cabinet in order to make the environment more sterile for different processes. The air passes through this filter and thereby traps fungi, bacteria and other dust particles. However, this filter is just a mat of randomly arranged fibers. These fibers are typically prepared from polypropylene or fiberglass with diameters between 0.5 and 2.0 micrometers. Because of this small fiber diameter, the HEPA filter ensures a sterile condition inside the cabinet.
Let's see how a laminar flow works:
- Here the working principle is based on the laminar flow of air through the cabinet. This simply means that air is moving at the same speed in the same direction.
- The device works by letting inward flow of air first passing through a pre-filter.
- Next, the blower or fan directs the air towards the HEPA filters.
- The HEPA filters then trap the bacteria, fungi and other particulate materials so that the air moving out of it is particulate-free air.
- Then the air passing through the filter is exhausted across the work surface as a part of the laminar flow of the air.
- External air with contamination cannot enter as the laminar flow cabinet is closed on the sides.
What types of laminar flow cabinets are there?
There are two kinds of laminar flow cabinets available for you to work in a laboratory. Their classification is based on the direction of the filtered airflow. You can choose the kind of cabinet you need based on the activities you would like to perform in your lab.
Horizontal laminar flow cabinets
These cabinets filter the air from outside the hood and blow the clean air from the back of the hood towards the operator. This creates horizontal airflow of particulate-free air. For us, as plant tissue culture enthusiasts, this type of cabinet is most suitable as it provides the most control over contamination.
However, it is important to know that we should not use this cabinet when we need to work with hazardous or infectious materials. As the airflow is in the outward direction, it does very little to protect us from harmful substances.
Vertical laminar flow cabinets
These cabinets not only filter the air from outside the hood, but also recirculates and filters the air from inside. However, clean air comes out in a downward direction over the workspace from the top. So this direction of air flow protects us from infections and it also protects the specimen from contamination. Thanks to the complete circulation of air within the workspace, researchers can work with different kinds of viruses or dangerous chemicals.
What are do's and don'ts while using a laminar flow?
Let us now talk about how to work with laminar flow or what we need to keep in mind to have an effective workflow:
- A key point about laminar flow is that they have a UV-C light lamp inside (Not all models in the market have this feature). It is there to sterilize the interiors before we use them in order to prevent contamination of the experiment. However, this light should always be off while we are using the cabinet.
- You need to sterilize the cabinet with UV-C light not only before use, but also after working in it.
- It is necessary to keep in mind that we don't use UV-C light and airflow of the cabinet at the same time.
- You should always have gloves, hair net and lab coat on while working with the cabinet.
- It is good to sterilize the workbench with alcohol before using the cabinet, in order to maintain a contamination-free work area.
- Any waste or other non-sterile items should be away from the cabinet workbench. These things create turbulence in the airflow and may create contaminations, which we don't want!
- You should not wear any jewelry/watches around your hands and wrists.
- You should not place large objects near the back of the cabinet as they may disrupt the laminar airflow and create contaminations.
- And the most important point to keep in mind is that you should never use non-sterile culture vessels inside the cabinet.
Let us now discover the different kinds of laminar flow systems you can find in the market and also on our webshop:
Standard laminar air flow cabinet
We have a standard horizontal airflow cabinet that has a minimalistic and clean design, while still offering all the advanced sterilization functions. It also has an airspeed measuring system and an automatic airflow compensation. Along with all these, it also has built-in UV-C light for sterlizing the workspace before starting daily activities.
Aside from these functions, our flow hoods provide a better HEPA filter life by using a combination of pre-filter and adjustable airflow settings.
Advanced laminar air flow cabinet
Apart from all the features already present in the standard version, the advanced version of our horizontal air flow cabinet also offers automated features. The automated features include a motor-controlled window blind and also a safety switch for UV-C light when the front glass shutter is open.
The biosafety cabinet is our most advanced flow hood. As a vertical airflow cabinet, it provides optimal protection for both specimens and users. Therefore, you will have little contact with the airflow within the working space. For those of you who want to work with harmful material, we highly recommend using a biosafety cabinet.
So this is all about why air treatment systems like laminar flow cabinets are one of the most important equipments you need in your lab. We hope that this brief description will be useful for many of you! Keep checking this space for informative articles!
By Nancy Bhatia | 09-June-2021