Direct examination is a simple, qualitative analytical method that looks at contaminated materials under a microscope to identify the types and spore counts of molds present. This analysis verifies visual indications of mold growth on materials. This can provide convincing evidence of colonization (mold growth on materials) that may be elusive with culture analysis.

Advantages:

• Confirms visual inspection findings
• Direct microscopic examination detects molds that are present without any biases caused by culture analysis
• Provides results in 24 hours
• Stronger indication than culture of colonization.

How it is used

The primary purpose of a direct microscopic examination is to determine whether or not mold is growing on the surface or within a material and to identify types of mold present. Direct examination distinguishes actual mold growth from the presence of scattered spores. The distinction is important because most materials collect a mix of spores that are normally present in the environment. These "table-top molds" are typical of non-problem areas, but will also be detected in culture analysis.

While culturing a material sample may help resolve a specific indication problem, culture analysis alone may result in an incomplete characterization. A direct microscopic examination provides a more detailed description of what is present without results being affected by an organism's ability or inability to compete and grow on a given media.

Helpful Links

Indoor Environment Notebook:mold clearance sampling

Fungi in Indoor Environments : Environmental & Occupational Disease Epidemiology : NYC DOHMH