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Hyphal Fragments: The Smoking Gun

So, you’re looking at your fungal certificate of analysis and you’ve hit the portion of the report that lists Insects Fragments, Pollen, and Hyphal Fragments. We know you don’t need a lot of help figuring out those first two, but Hyphal Fragments? That’s probably a new one for you and that’s exactly what this blogpost is for.

First, let’s get some vocabulary out of the way:

  • “Hyphae” (pronounced HI-fee) make up the fungal structures that produce spores. 
  • “Hyphal Fragments” (pronounced HI-full) are what we call broken up Hyphae. 

We like to explain that Hyphae and Hyphal Fragments are the “smoking gun” for the presence of whatever spores may be in your home. (Fun fact – Penicillium is named for the Latin word for “paint brush” because of its paintbrush-like appearance under a microscope.) So, picture a paint brush with us and imagine spores are produced then released from the tip of every bristle. That entire paintbrush you’re picturing would be considered Hyphae. Smash the paintbrush and you’ve got Hyphal Fragments. 

Most molds, including that paintbrush-like Penicillium, go through a growth phase where they aren’t making any spores at all. It’s all Hyphae. It’s totally possible… even probable, then… that air and surface samples of a moldy environment will show the presence of Hyphal Fragments. And that may occur with or without spores. Microbiologists typically need to see some spores to be able to identify which mold is growing, but the presence of Hyphal Fragments can be enough to say that mold is growing (but check with your home inspector, assessor, or environmental consultant for a full interpretation of your reported results).

We get a lot of questions asking why our report indicates “Growth Likely” when there are only a handful of spores and significant numbers of Hyphal Fragments present. We hope this analogy- and imagery-packed blog post clarifies some of that for you. If not, Daane Labs microbiologists are just one email or phone call away.