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LAF ( Laminar Air Flow) Chamber Introduction

A LAF Chamber/ cabinet or tissue culture hood is a carefully enclosed bench designed to prevent contamination of semiconductor wafers, biological samples, or any particle sensitive materials where the air is passed through a HEPA ((High-Efficiency Particulates Air) filter which removes all airborne contamination to maintain sterile conditions as shown above image.

LAF Chamber working mechanisms

LAF chamber consists of filter pad, fan, and  HEPA filter. The fan sucks the air through the filter pad where dust is trapped. After that the prefiltered air has to pass the HEPA filter where contaminating bacteria, fungi, dust, etc. are removed. Sterile air flows into the working area where you can do all your work without the risk of contamination.  It is normally made of stainless steel with no gaps or joints thereby preventing the build-up of bacteria from collecting anywhere in the working zone. It is also known as clean benches because the air for the working environment is thoroughly cleaned by the precision filtration process.

LAF chamber  types

It can be produced as both horizontal and vertical cabinets. There are many different types of cabinets with a variety of airflow patterns for different purposes.

• Vertical Laminar Air Flow Cabinets
• Horizontal Laminar Air Flow Cabinets

Parts of Laminar Air Flow Chamber

1. Blower: It assembly draws room air through pre-filter and throws towards HEPA filter.
2. Pre Filter: It is the primary air filter that filters room air initially and forward towards the HEPA filter. Usually, pre-filter keeps out particles 5 µ or higher.
3. HEPA Filter: This is the final filter. Air filtered through pre-filter is forwarded towards HEPA filter. HEPA filter offers 99.99% efficiency for 0.3-micron particulates.
4. Pressure gauge: Magnehelic gauge is used to monitor the differential pressure across the HEPA filter with respect to ambient.
5. Workbench: It is made of stainless steel. Samples/products are put on it for work.
6. Sash: It is a sliding front door. Users can slide it manually and adjust the opening height as needed.
7. Light: It is fitted to provide proper illumination under the working area.
8. Service fixtures: The main chamber is fitted with an electrical socket, air, and gas cock.
9. Germicidal UV lamp: A UV lamp is an added option that is used to sterilize the working area prior to use. It is advised no contact to make in the chamber during this time.

Application of LAF Chamber

LAF systems are used in various applications such as-

1. Life science research
2. Microbiology
3. In vitro fertilization (IVF)
4.  Intrauterine Insemination (IUI)
5. Histopathology or pathology laboratory
6. Plant tissue and cell culture
7.  Pharmaceutical
8. The electronics industry, etc.

Care and maintenance of LAF chamber

• Before you start working in your laminar flow hood you should do the following actions-
• Turn on the blower and wipe out the sterile area with an alcohol-soaked piece of kitchen paper.
• Let the blower run continuously for 30 minutes.
• When this time has passed, wipeout out the sterile area with an alcohol-soaked piece of kitchen paper.
• Important parameters to make sure that the hood works efficiently: the HEPA filter has to remove all airborne materials and the airspeed in the working area has to be between 0.3 m/s to 0.5 m/s.

References

1. https://www.lamsys.com/products/vertical_laminar_flow/
2. https://www.stericox.com/cleanroom-equipment/laminar-air-flow.html
3. https://thermolabscientific.com/other-products/laminar-air-flow-