Laminar Flow Cabinets

Laminar flow cabinets, commonly referred to as tissue culture hoods or laminar flow hoods, are self-contained enclosures designed to protect sensitive materials from exposure to particulate or microbial contamination. It's a relatively simple device that utilises HEPA filtration to produce a stream of laminar flow air over the internal worksurface, thereby shielding workspace samples from contamination.

The first concept of "laminar flow air" originated during the late 1950s. Willis Whitfield developed the first laminar flow cleanroom in 1959 during his tenure at Sandia National Laboratories. Essentially, you can think of a laminar flow cabinet as a small-scale cleanroom with an ISO rating to match the level of cleanliness the workspace provides. While some laminar flow cabinets create ISO 4 cleanroom conditions, others create ISO 5. The level of cleanliness you need depends on the application or process the product is required for.

In theory, these devices also function similarly to a biosafety cabinet. However, unlike a biosafety cabinet, laminar flow cabinets do not protect the operator, only the sample. For example, if you have an application involving a benign, non-toxic material, a laminar flow cabinet would be a suitable device. On the other hand, if the material is potentially hazardous or zoonotic in nature, a class I, II or III biosafety cabinet would need to be used.

A laminar flow cabinet works by streaming particle-free air over the workbench at a smooth, uniform velocity. The cabinet uses HEPA or ULPA filters to remove airborne contaminants and create ISO cleanroom conditions, minimising the risk of contamination. It's important to note that laminar flow cabinets, unlike PCR cabinets, also use pre-filters as an additional line of defence.

So, how is it built? The product features three enclosed sides with a frontal access port and a centrifugal fan located at the back (horizontal) or top (vertical) of the cabinet. The type of unit you choose should depend on the needs of your application. For example, the horizontal system reduces turbulence on the work surface, making it ideal for small-scale samples.

Laminar flow cabinets can use HEPA and ULPA filters. However, the type of filter you choose depends on the process taking place inside your cabinet. While ULPA filters are more accurate, HEPA filters are a cost-effective and widely available alternative commonly used throughout the industry. For more information on the benefits of HEPA filters, please visit "What Are HEPA Filters and How Do they Work?".

No. Laminar flow cabinets are designed for use with passive, non-toxic materials. The cabinets only protect the sample, not the user. Common applications include semiconductor testing, media preparation, mycology and plant tissue culture. For more information visit "What Are Laminar Flow Cabinets Most Commonly Used For?"

A laminar flow cabinet can take between two to four hours to install. It's designed as a simple plug & play system, allowing engineers to position and commission the unit without the need for external ductwork.

A laminar flow cabinet will cost between £4,000 to £6,000, depending on the complexity and size of the unit. Our laminar flow cabinets include HEPA H14 filters as standard.

While PCR cabinets use UV to sterilise the environment, LAF cabinets use an air-cleaning filtration system (HEPA or ULPA). The technology removes any particles on the work surface, ensuring a contamination-free environment. There are two separate models available:

• Horizontal Laminar Flow Hood – Air is projected horizontally across the work area directly out of the front of the cabinet.
• Vertical Laminar Flow Hood – Air is projected downward, and then across the work surface and out of the unit.

Remember, laminar flow cabinets are produced to protect materials inside the workspace. They do not protect laboratory technicians and are not suitable for working with biohazards. To do this, you would need a class II biosafety cabinet.