For those of you who work in a laboratory, a hood laminar is not only an exotic term, but it is your first line of defense against contamination. A laminar flow hood is a clean, controlled environment that pulls filtered air in one direction, preventing dust/microbes/particles from coming near your samples. In microbiology, tissue culture, pharmaceutical, and research laboratories, selecting the appropriate laminar hood for use in the Lab has direct implications for the quality and reliability of your results.
What Is It And How Does It Work: Hood Laminar?
A hood laminar (also called a laminar hood or laminar flow hood) is a cabinet that blows air in the work area in a smooth, uniform laminar flow. This air flows first through a HEPA filter laminar hood system, which removes most airborne particles, then passes continuously over the work area and out away from the critical area.
Since the flow of air is constant and one-way, it prevents contaminated room air from entering the working area. This makes the laminar hood for the microbiology lab perfect for plating, pouring media, inoculations, and handling sterile materials.
Types of Laminar Flow Hoods- Horizontal vs Vertical
In the Lab, you will find two configurations mostly.
1. Horizontal laminar flow hood
In a horizontal laminar flow hood, filtered air flows from the back of the cabinet to the user. It provides excellent protection for the samples because the air passes directly over the work surface and outwards. However, it doesn’t offer much protection to the user, so it’s suitable where product protection is essential. Still, there’s little risk of biohazards, such as in electronics assembly or non-pathogenic cell culture.
2. Vertical Laminar Flow Hood
In a vertical laminar flow hood, air moves from the top to the bottom, resembling a mini-cleanroom. This design reduces direct airflow towards the user’s face, making it safer in some laboratory operations. A lot of modern laboratory designs for laminar air flow cabinets incorporate a vertical flow, as this is more space-efficient and provides improved ergonomic access to the cabinet (a wide problem when dealing with very tall flasks or instruments).
Some people confuse laminar hoods with whole-biosafety laminar hoods, also known as biological safety cabinets. A laminar flow hood is a basic hood primarily designed to protect the product from contamination. A biosafety cabinet, on the other hand, is a specialized hood that protects the product, the person using it, and the environment, particularly when handling infectious agents.
Importance of a Hood Laminar for the Laboratory
A properly-maintained laminar flow hood is an essential equipment in:
- Microbiology and bacteriology: A laminar hood for a microbiology lab used for streaking plates, using culture media, and preparing sterile solutions.
- Tissue culture and Cell biology: This system protects sensitive cells against contamination by dust, spores, and microbes.
- Pharmaceutical and cosmetic testing: Maintains aseptic conditions when preparing samples, filling, or checking quality conditions.
- Research and Development: Any Research and Development process that requires a low contamination environment, ranging from filter testing to minor device assembly.
By providing a consistently clean air zone, the hood laminar flow increases the reliability of experiments, decreases the work required to repeat an experiment, and helps maintain regulatory standards.
Safety & Best Practices of using Laminar Hood
Even the best hood laminar for a laboratory will not work successfully if it is misused.
It is best to follow the following guidelines to ensure that your laminar flow hood continues to work and perform its job safely:
- Prepare the working surface: Clean the work surface with suitable disinfectants before and after working.
- Pre-Operational Balance of the Hood: The hood airflow must be operated for a few minutes before use to allow it to stabilize.
- Work in the clean zone: Critical items must be kept in the middle of the airflow area and not pushed up against the sides, or so close to the front.
- Avoid blocking the airflow: Do not stack bottles or instruments in a way that creates air shadows behind them.
- Fast-moving hands will cause turbulence and suck contaminated air into the working area, so avoid fast-moving hands.
- Follow the maintenance guide provided: inspect the filter, perform airflow tests, and clean regularly as suggested by the manufacturer.
For higher-risk biological work, always ensure that you require a biosafety laminar hood or a proper biosafety cabinet as an alternative to a basic laminar flow hood.
Final Thoughts
A hood laminar isn’t just any piece of furniture in the Lab; it is a controlled microenvironment that helps protect your samples and ensures proper, accurate, and reproducible results. Understanding the difference between horizontal and vertical laminar flow hood designs, along with knowing when to use a standard laminar hood versus a biosafety hood, will go a long way in keeping your laboratory work cleaner, safer, and more professional in terms of safety and maintenance practices.
