DIRECT EXAM SAMPLING GUIDE (TAPE LIFT, BULK, SWAB, WIPE)
Tape lift, bulk and swab sampling, are techniques used for direct examination. A direct exam allows for the immediate determination of the presence of fungal spores as well as what types of fungi are present. Direct examinations should only be used to sample visible mold growth in a contaminated area since most. Most surfaces collect a mixture of fungal spores that are normally present in the environment.
1. The direct exam is inexpensive, and can be performed quickly.
2. A useful test for initial site sampling.
3. Direct examination of a surface indicates all mold present in a given area.
4. Direct sampling may reveal indoor reservoirs of spores that have not yet become airborne.
1. Areas of fungal growth are often small and scattered, so they may not be picked upon sampling.
2. Health problems related to indoor microbial growth are generally caused by the inhalation of substantial numbers of airborne spores, sometimes over a long period of time. The presence of biological materials on a particular surface, is not a direct indication of what may be in the air.
3. Not all the spores seen under the microscope may be viable (alive). It is advisable to combine direct exam samples with culture methods to get a better picture of what molds are present.
4. Tape lifts are not able to be cultured.
5. If a direct examination of a swab sample is taken, there is no follow up culture.
6. Direct examinations of dirt/soil and dust samples can not be performed.
For Tape lift:
1. Clear (transparent) Scotch or other brand tape (frosted tape hides the spores).
2. New plastic bag to hold specimen(s) (provided in a tape lift kit available from LA Testing).
1. Sterile container or new plastic bag or Whirl-a Pack (provided at your request by LA Testing) to hold and transport specimen.
Sterile culturette/swab with appropriate buffer solution to collect and transport specimen (provided at your request by LA Testing).
For all matrices:
Latex/nitrile gloves (also can be provided at your request).
1.Take a few inches of clear tape. Avoid touching the sticky side, especially the part touching the mold.
2.Wearing gloves, apply the central inch of tape to the suspect area (choose one that is free of extraneous debris). Apply light pressure to the non-adhesive side.
3.Pull tape off surface with slow, steady pressure, holding the tape edges only.
4.Apply sticky side of tape to the inside of the plastic bag.
5.Ensure there are no folds or creases in the tape.
7.Put only one sample in each bag.
1.Wearing latex gloves, take a small piece of the suspect material.
2.Place piece inside clean sterile container or new plastic bag or whirl-a-pack bag.
3.Close bag or cap container.
1.Wearing gloves, remove swab from packaging material.
2.Remove plug from media tube.
3.Swab the desired area thoroughly, rolling the swab lightly back and forth over sampling area.
4.Insert the swab in the tube, and firmly close cap.
For all matrices:
1.Label each sample with appropriate information.
2.Complete a microbiology Chain of Custody (COC) detailing client name and information, project name or number, sample #, and a description of the area.
QUALITY CONTROL SUGGESTIONS
1. Use clear tape, not frosted.
2. Do not fold tape onto itself.
3. Stick tape on the inside of the plastic bag only.
4. Please do not send tape lift samples on slides or coverslips. They may arrive broken making the sample difficult to analyze.
1. Send a representative sample of the specimen if large. This prevents over-handling of the specimen and possible contamination. If analysis of a specific portion of sample is required, please note area(s) or take a tape lift of area.
1. For semi-quantitative sampling, the area swabbed needs to be entered on the chain of custody.
For all matrices:
Apply tape, apply swab, or take a small piece of material ONLY from areas where visible mold is seen.