There are two primary methods of surface testing: swab and tape lift. Both are easy to perform and can be done with inexpensive kits or lab-supplied materials.

Swab sampling is typically used on:

• Porous or uneven surfaces (grout, caulk, wood grain, fabrics).
• Areas where moisture may be trapped or absorbed.
• Surfaces with visible growth or staining.

To collect a swab sample:

1. Use a sterile swab (typically provided by the lab).
2. Rub the swab firmly over the discolored area in a crisscross motion.
3. Place the swab in the provided tube or sterile bag, seal, and label it.
4. Ship to the lab following their instructions.

Tape lift sampling works best on:

• Smooth, flat surfaces (glass, tile, painted drywall, sealed wood).
• Items with suspected surface dust or residue.
• Situations where you don’t want to damage the surface.

To collect a tape lift:

1. Use clear adhesive tape (such as lab-supplied or clear packing tape).
2. Press the sticky side onto the suspect area using firm, even pressure.
3. Lift the tape straight off and stick it to a labeled microscope slide or plastic backing.
4. Send it to the lab in a sealed container.

Make sure to include enough detail in your labeling to match the sample to the area it came from. Good recordkeeping makes interpretation much easier later on.