A laminar flow cabinet or tissue culture hood is a partially enclosed bench work surface designed to prevent contamination of biological samples, semiconductor wafers, or any particle sensitive materials. Air is drawn through a HEPA filter and blown in a very smooth laminar flow in a narrow vertical curtain, separating the interior of the cabinet from the environment around it. The cabinet is usually made of stainless steel with no gaps or joints where spores might collect.
Despite their similar appearance, a laminar flow cabinet should not to be confused with a fume hood. A laminar flow cabinet blows unfiltered exhaust air towards the worker and is not safe for work with pathogenic agents, while a fume hood maintains negative pressure with constant exhaust to protect the user, but does not protect the work materials from contamination by the surrounding environment.
