Mold Identification Photographs of Mold Growing on Petri Dishes or Mold Culture Plates or Settlement Plates
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• Can photos provide reliable identification of mold on culture plates or petri dishes?
• Limitations of mold cultures as a "mold test kit"
• Usefulness of culturing for the identification and study of mold
• 90% error rate in capture of mold genera/species with some mold test methods
• Do all molds grow on culture?
• Do all mold spores settle out of air at the same rate onto culture plates?
• Are all mold spores equally important in mold samples?
• Questions & answers about using culture tests for building mold contamination

Question:

I was disappointed as there were no photos at all of petri dish examples of mold, and this is the way most of us out here will be testing for mold. So, how do I explore what mold I have in my petri dish test? I have quarter sized discs of black/dark green mold growing. I did the airborne mold test.

My dog is always coughing and I am in pretty good health but feel a slight "tug" in my breathing, a slight heaviness in my lungs but not bad. I rent my apartment and my landlord is a total tool.

What can I do financially and health wise to explore my situation? Thanks for any tips!!! - Tony K

We do have some photos of mold in petri dishes posted just above and online, at other of our online articles about the role and limitations of using mold cultures as "home test kits" at Cultures to "Test for Mold". (You'll see there that what grows in culture is not necessarily the dominant or most significant mold that is present in a building.)

Traditionally, petri dish or culture plate photos were included in early mold taxonomy texts, where color and texture of mold growth at that scale assisted in identification of cultures of a known genera down to species level.

These were photos of mold cultured in laboratories where it is sometimes possible to separate a genera of mold (Aspergillus sp.) into species or groups of species (Aspergillus niger) based on color and other macro-characteristics.

In the closeup of a mold culture petri dish growth shown in our photo at above-right, high-powered microscopic examination was necessary to identify Penicillium sp (photo at left) as one of the several mold genera growing among these green, gray,and dark gray colored mold colonies.

Sometimes we can make a pretty good guess about mold identification by the naked eye, if we see a particular color and texture of mold on a particular surface. For example this photo of mold on an orange is showing what is most likely a species of Penicillium.

But in general that "by eye" mold identification approach is not reliable.

An "in-between" level of magnification, between using the naked eye to look at mold culture growing in a petri dish and using a high powered microscope is the use of a stereo microscope to magnify mold growth on surfaces such as on culture media in a petri dish.

For example, our stereoscopic microscopy photo of Fuligo septica (left) is characteristic of that particular fungus.

Stereoscopic mold photos are often beautiful (like this stereoscopic photo of Stemonitis mold growth structures taken in our lab) and may be helpful in identifying a mold genera. Here, for contrast, is a high power microscope photo of Stemonitis mold spores.

But stereoscopic magnification is inadequate for reliable mold identification.

For environmental samples in which we need to identify mold genera/species or other particles, it's a different story.

As we operate a forensic lab that processes lots of materials including mold, collected by various means, we see that while petri dish photos are pretty, they are not diagnostic, nor can they be used alone for mold identification at that scale.

We need to examine mold structures and spores at 300x to 1200x to actually identify genera/species reliably. See MOLD BY MICROSCOPE for examples.

The Fuligo septica mold spores in our photo provide very different information than what we can get by eye looking at a mold culture plate or petri dish.

Also see more photos at MOLD ATLAS & PARTICLES INDEX and our Alphabetic Index to Mold Genera or Species

At MOLD "TESTING" vs. MOLD "PROBLEM IDENTIFICATION" we discuss the question of what sorts of mold testing are most useful and which are actually diagnostic, giving information about the presence of a mold problem with enough information that you know what to do about it.