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NC State Extension

Submitting Samples From a Residential or Commercial Building

beach house

A good sample is essential for an accurate diagnosis. Please follow these instructions carefully. The instructions on this page apply to the appropriate collection of arthropods (insects, spiders, mites, etc.), small invertebrates, and indoor molds from residential and commercial buildings.

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To sample arthropods (insects, spiders, mites, etc.)

  • For most arthropods, including cockroaches, termites, bugs, beetles, flies, wasps, ants, maggots, spiders, mites, etc., specimens should be collected and killed in a well-sealed vial or other container that has ≥ 70% ethyl or isopropyl alcohol inside. For shipping purposes the vial/container should be double bagged in plastic zipper bags.
  • Butterflies and moths should be sent in dead (killed in the freezer), and packaged lightly in tissue paper in a crush-proof box. Do not put in alcohol.
  • For instruction on collecting worms, slugs, snails, and other soft-bodied invertebrates, please see the unknown creature page.

If a photograph of the organism can be taken with clarity and magnification (e.g. microscope camera) from several views/angles, images alone may be enough to determine the organism. Image samples are free to submit to the PDIC (preferably through the database), although if a follow-up physical sample is required, the sample will incur a standard fee.

Identification of indoor molds

  • The preferred method for submitting household mold samples is on cotton swabs.
  • For each affected area, take a new cotton swab and rub gently across the moldy/stained surface.
  • Label a sealable plastic bag with the location (e.g. “windowsill in back bedroom”, “floor joist in crawlspace”) and place the swab inside. Place only one swab in each bag.
  • It’s helpful to get a piece of the material (wood, sheetrock, fabric) on which the mold was growing, when this is practical. For wood, a chisel can be used to remove a piece about 1/8″ to 1/4″ thick and a few inches long.
  • Online data entry for mold ID samples is basically the same as for other kinds of samples. Use the following options: Host site type=“Household”; Host=“Household; Domestic Dwellings; Habitat”; Problem type=“Other”.
  • Explain the situation completely in the Comments section, including a list of the individual sites for which swabs are being submitted.
  • With each sample number (form submission) up to five items can be submitted, in any combination of swabs and pieces of moldy material, taken as described above.