Different Flow Hoods and How They Are Used in Experiments

                                                     Working in a laminar airflow cabinet. Image by Tim Sandle

What is a flow hood? It's a controlled environment created to minimize contamination, and it does this by directing filtered air over the designated workspace. Flow hoods are also known as clean benches or laminar flow hoods. Regardless of what name they go by, they're frequently used in laboratories to provide a sterile environmental setting for experiments by protecting researchers, equipment, and samples from airborne contaminants. Particle removal happens through ultra-low penetration air or high-efficiency particulate air filters before the air comes into the workspace. Flow hoods are available in several categories, and knowing their differences is crucial to picking the best hood for a particular application.

Different Flow Hoods and Their Uses in Experiments

You can find a variety of flow hoods for different applications. Knowing the primary categories helps you sift through your options.

Laminar Flow Hoods

A laminar flow hood makes a steady stream of filtered air. This stream moves continuously in a single direction to keep contamination from happening. Laminar flow hoods come in both horizontal and vertical configurations. Horizontal models direct clean air across a work surface and toward the user, and they're often used in pharmaceutical research, electronics assembly, and microbiology. Vertical models push filtered air down to the work surface to keep contaminants off of users; these are ideal for sample preparation and tissue culture work.

Biological Safety Cabinets

BSCs are intended to protect experiments, users, and the surrounding environment around them. HEPA filtration captures hazardous particles. Biohazard exposure is further prevented by airflow containment systems. BSCs are available in three different classes with varying levels of environmental protection. The highest levels of containment are totally enclosed and feature glove ports for handling dangerous pathogens.

Fume Hoods

Fume hoods aren't designed to be sterile, but they can prove important for any experiment that involves volatile chemicals. Users are protected when hazardous fumes get drawn away from a workspace and vented safely outside. Chemistry laboratories frequently employ these to minimize exposure to many different toxic substances.

PCR Workstations

Polymerase chain reaction workstations are a special category of laminar flow hoods. These are intended to minimize DNA contamination when amplification processes are underway. UV light is a common sterilization technology between experiments.

What To Watch Out for With Flow Hoods

There are several considerations to be mindful of with flow hoods. First, airflow disruptions can reduce effectiveness when objects are placed incorrectly in a flow hood. Secondly, ULPA and HEPA filters degrade with the passage of time; regular checks and replacements are essential to maintaining proper efficiency and function. Third, work practices need to be good habits in terms of avoiding rapid movements that might introduce contaminants or opening and closing flow hoods too frequently.

Proper hood selection is always important. Using the wrong kind of hood for your experiments might compromise the final results. For instance, don't use laminar flow hoods when working with hazardous materials. A biological safety cabinet is the more appropriate choice.

Protect Your Experiments

Flow hoods are important to experimental settings because they offer controlled environments with improved precision and safety. Choose the appropriate hood for your conditions and maintain it properly for reliable performance in laboratory settings and research applications.

Written by Taylor McKnight, Author for Cleatech LLC

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)