In this laminar flow biosafety cabinet (with diagram) post we have briefly explained about components, principle, procedure, types, uses, advantages, and disadvantages of laminar flow chamber.
What is Laminar Flow Cabinet?
Laminar flow chamber (figure 1) is an enclosed workstation that is used to create a contamination-free work environment through filters to capture all the particles entering the cabinet. It is possible to carry out aseptic procedures without laminar air flow if you have appropriately isolated, clean accommodation with restricted access. However, it is clear that, for most laboratories, which are typically busy and overcrowded, the simplest way to provide aseptic conditions is to use a laminar flow chamber.
Figure 1: Laminar Flow Biosafety Cabinet
Components of Laminar Cabinet
A fan is present below the filter pad that sucks in the air and moves it around in the laminar flow chamber. The fan also allows the movement of air towards the HEPA filter sp that the remaining microbes become trapped while passing through the filter.
b. Pre Filter
It is primary air filter which filters room air initially and forward towards HEPA filter. Usually, pre filter keeps out particles 5 microns or higher.
c. HEPA Filter
This is final filter. Air filtered through pre filter is forwarded towards HEPA filter. HEPA filter offers 99.99% efficiency for 0.3 micron particulates.
d. Pressure gauge
Magnehelic gauge is used to monitor differential pressure across HEP filter with respect to ambient.
c. Work bench
A flat working station is present inside the cabinet for all the processes to be taken place. Culture plates, burner and loops are all placed on the working station where the operation takes place. The worktop is also made up of stainless steel to prevent rusting.
d. UV lamp
UV lamp is an added option which is used to sterilize working area prior use. It is advised no contact to made in laminar flow chamber during this time.
e. Air Filtration
The efficiency of a Laminar Air Flow workstation depends upon the quality of pre filters and HEPA filters. In our LAF, the Air filtration system is created to work efficiently even in critical environment. Pre filter that we use are box type pleated having efficiency 95% down to 5 micron and made of HDPE + Non-woven + HDPE mesh media and fitted in aluminium case. The HEPA filters are of high quality having efficiency 99.99 % down to 0.3 micron and fitted in aluminium anodized case. The blower assembly has ¼ HP; 1400 RPM branded motor and has aluminium anodized impellers.
d. Work Area
The working area is carefully designed for comfortable working and easy cleaning. The workbench is made of stainless steel. Standard fittings are air/gas cock and electrical outlet. For illumination, we use fluorescent lamps. Front side of working area is covered by manual sliding door (sash), which is made of transparent acrylic plastic. There are some optional features that can be added if required by customer. LCD display for air velocity, time and lamp on/off status are displayed on it. Germicidal UV lamp, extra electrical socket and magnahelic gauge are also fitted if required. If you want to know about laminar air flow price, customization, installation and validation etc. please email us your detailed query. Our sales personnel will contact you with everything you need.
Principle of Laminar Cabinet
Laminar Air Flow is also known as clean benches because the air for the working conditions is thoroughly cleaned by the precision filtration process. Laminar air flow operates by the use of in-flow laminar air drawn through one or more HEPA filters, designed to create a particle-free working environment and provide product protection.
Air is taken through a filtration system and then exhausted across the work surface as part of the laminar flows process. Commonly, the filtration system comprises of a pre-filter and a HEPA filter. The Laminar Flow Cabinet is enclosed on the sides and constant positive air pressure is maintained to prevent the intrusion of contaminated room air.
Procedure of Laminar Cabinet
Before starting the laminar air flow, be sure there is nothing within that is susceptible to UV radiation. Laminar flow chamber glass shield is then closed, and the UV light is turned on. The UV light should be left on for around 15 minutes to ensure that the working bench’s surface is sterilised.
The UV light is then turned off, and a 10-minute wait period is allowed before the airflow is turned on. The airflow is turned on about 5 minutes before the surgery begins, after it has been sterilised with additional disinfectants such as 70% alcohol.
The glass barrier is then removed, and the fluorescent light is turned on for the duration of the procedure. Other disinfectants, such as 70% alcohol, might be used to sanitise the cabinet’s operating bench for added protection. The airflow and florescent lighting, as well as the glass shield, are both closed once the task is completed.
Types of Laminar Cabinet
a. Horizontal Chamber
In Horizontal Laminar Flow Cabinets airflow in a horizontal direction across the working area (Figure 2B). The continuous air flow provides material and product protection. The surrounding air enters the horizontal laminar flow chamber from behind the working bench and is projected by the blower towards the HEPA filters. The filtered air is then exhausted horizontally into the work environment. One advantage of this cabinet is that airflow parallel to the workplace continuously cleanses the environment. The elluent air directly hits the operator, potentially lowering the security level of these laminar flow chamber.
b. Vertical Chamber
In Vertical Laminar Flow Cabinets filtered air flows vertically downwards onto the working area (Figure 2A). The air can leave the working zone via holes in the base. Vertical flow cabinets can provide greater operator protection. A horizontal-flow laminar flow chamber is cheaper and provides the best sterile protection for your cultures, but it is really suitable only for preparing medium (without antibiotics) and other nontoxic sterile reagents and for culturing non-primate cells. It is particularly suitable for dissecting non-primate material for primary culture. For potentially hazardous materials (any primate, including human, cell lines; virus-producing cultures; radioisotopes; and carcinogenic or toxic drugs), a Class II or Class III microbiological safety cabinet should be used. In practice, most laboratories now use a Class II microbiological safety cabinet as standard.
Applications of Laminar Cabinet
- In laboratories, laminar flow cabinets are used for contamination-sensitive activities like plant tissue culture. Other laboratory activities, such as media plate preparation and organism culture, can be done inside the cabinet.
- Drug preparation processes are also performed within the cabinet in the pharmaceutical industry to maintain a particulate-free environment during operations.
- Laminar flow cabinets can be created to order for specific projects, but they can also be utilised for general lab techniques in the microbiological and industrial fields.