Direct Examination
______________________________________________________________________________
Fungal Sampling Information
Non Fungal Sampling
Information
Chain of Custody (Normal)
Qualtest, Inc.   2458 Alton Parkway   Irvine, CA   92606 Phone: (949) 838-0378
Contact Us
Introduction

    Direct examination is used to sample visible fungal growth in a suspected
    area. This sampling method is usually the best method of analysis for surface
    samples. Direct examination of a surface shows exactly what is there. Our
    qualified analysts will examine the sample to identify any fungi that is
    actually growing on the surface samples. The results are qualitative and
    descriptive.

  • The direct exam is quick, accurate and inexpensive.
  • A useful test for initial site sampling.
  • Direct examination of a surface indicates all fungi present in a given area.
  • May reveal indoor reservoirs of spores that have not yet become airborne.

The methods used for direct examination are tape lift, bulk, swab and dust
sampling.

  1. Tape Lift

  • Where/when to use
On flat, dry surfaces with visible fungal growth.
Used on surfaces such as drywall, wallpaper, lumber, ceiling tiles, ect.
Do not use it for carpets, air duct liners or wet surfaces.
  • A clear piece of tape is used to collect a sample from the surface.
  • Wearing gloves during sampling is required.
  • Easy to sample, process and analyze.
  • Quick turn around time.
  • The major advantage of this method is that fungi are detected and
    identified whether they are dead or alive.
  • The detection of fungi on a particular surface is not a direct indication
    of what may be in the air.
  • Tape lift samples cannot be cultured.

2.  Swab

  • The samples are collected by wiping an area using a sterilized swab.
  • Wearing gloves during swab sampling is required.
  • Swabs are usually used on wet surfaces.
  • Swabs are the best way to sample when the sampling area is difficult to
    reach or a bulk sample is not practical.
  • Swabs can cause damage to fungal structures (fruiting structure and
    hyphal fragment) during the processing of the sample.

3.  Bulk

  • Bulk samples are collected by removing a one or two square inch piece
    of the suspected material, then placing it inside a clean plastic bag.
  • To prevent mold from one sample getting onto another sample,
    samples are collected in separate bags.
  • Avoid breathing in fungi or fungal spores. Wear gloves and goggles
    while sampling bulk materials.

Interpretation of Results

  1. Tape lift, bulk and swab samples taken for direct examination will provide
    qualitative and descriptive results. The purpose of this procedure is to
    determine whether fungi are present and to identify the fungi and their
    concentrations.
  2. The results do not indicate whether the detected fungal structure is viable or
    not.
  3. The detection of a few loose fungal spores suggests fungal growth in the
    vicinity.
  4. The detection of spores and conidiophores suggests possible fungal
    contamination or growth.
  5. The detection of fungal hyphal fragments, mycelium and other fungal
    structures suggests fungal growth.
  6. The detection of conidiophores, hyphae and spores suggests fungal growth.
  7. The concentrations of fungal growth are described as "massive", "numerous",
    "many", "a few", "a trace", and "no obvious fungal growth". There descriptions
    are subjective and based on the analyst's experience and observation of the
    sample.
  • Massive: is used to describe a very heavy and dense concentration of
    fungal structures. Fungal structures cover the entire sample or viewing
    area in more than one layer.
  • Numerous: is used to describe heavy and dense concentrations of
    fungal structures too numerous to count. One layer of fungal structures
    covers the entire sample or view area.
  • Many: is used to describe fungal structures that are heavy but
    countable. Fungal structures cover 25% to near 90% of the sample or
    viewing area.
  • A few: is used to describe detectable and measurable fungal structures.
    Fungal structures are consistently detectable and countable, and covers
    up to 25% of the sample or viewing area.
  • A trace: is suggesting that fungal structures are barely detectable by an
    experienced mycologist. It may be missed by less skilled analysts.
    Fungal structures are detectable when carefully examined by one
    analyst, but may be missed by another analyst.
  • No obvious fungal growth: is used to describe no fungal growth
    observed.
8. The background (debris, dust and/or skin flakes) on a sample is described
as:
  • Low: 1-25% of the of the sample is covered by above debris.
  • Medium: 26-75% of the sample or view area is covered by above
    debris.
  • High: >75% of the view area is covered by above debris.
9. Some Indicator Spore Types
  • Species of Chaetomium Eruotium, and Peziza are frequently found on
    water damaged paper or wood products.
  • Several Basidiomycetes may be identified on water damaged wood or
    paper products in buildings. These Basidiospores cause wood decay, a
    condition that can dramatically reduce the structural integrity of a
    building.
  • Stachybotrys and other certain types of fungi, such as Aureobasidium,
    Chaetomium, Fusarium, Trichoderma and Ulocladium are an indication of
    water damage.
  • Ceratocystis/Ophiostoma: Lumber mold is present on the wood framing
    of most homes that are built with lumber. Their presence alone is inot
    indicative of an indoor water problem.
______________________________________________________________________________
Qualtest, Inc.