Below you will find information to aid you in requesting swabbing materials from NQAC, collecting swabs for allergen cleaning validation, and shipping completed swabs to NQAC for analysis.
Requesting Swabbing Materials from NQAC Dublin
NQAC provides the following Materials:
- Neogen Allergen Environmental Swabs (part # 8432S) or equivalent Copan Swab part 159C – Strongly recommend swabs listed above which are intended for allergen testing to capture trace levels of allergens and not cross react with the allergen test kit. Do not use swabs or sponges intended for microbiology sampling.
- Allergen spike solution in 2 mL centrifuge vial – The spike is specific to the allergen being tested. The expiration date is printed on the vial. Each vial can only be used for 1 swab.
*NOTE: You will need sterile deionized (DI) water and disposable Pasteur pipettes not provided.
Storing Allergen Swabs Upon Receipt:
The allergen spike vials must be stored in the freezer immediately upon receipt. They must remain in the freezer until ready to swab. Spike solutions that are kept frozen are acceptable until the expiration date on label.
Collecting Allergen Swabs
Definitions:
Blank swab: Unused swab analyzed as a check for false positives or contamination.
Positive control swab: Unused swab with the allergen spike solution. This control checks that the test materials are functioning, and that the allergen could be detected if it were present.
Interference check swab: Unused swab with environmental surface residue from adjacent sampling area and allergen spike solution. This control checks for interference from residues that might be present on the surface of the equipment. This check is recommended due to some cleaning solutions causing false negative results.
Swabbing Procedure:
- Set aside three swabs for quality control for every batch of swabs collected – Interference, blank and positive.
- Remove two allergen spike vials from the freezer to thaw before use. One spike vial per individual spike control swab.
* Keep spike vials separate from the swabbing area to avoid cross-contamination with allergens*
- To collect a swab sample, label swab and use it to swab surface to be tested. If the surface is dry, use disposable Pasteur pipet to add 2-3 drops of sterile water to swab. Swab in a zigzag motion, covering the entire area 10 x 10 cm (4 x 4 in) swabbing area is suggested. Immediately after swabbing return the swab to the tube and add an additional 2-3 drops of sterile DI water. Mark the tube with the sample identity.
Examples of acceptable & unacceptable DI water addition to swabs
- Blank swab – mark one reserved swab “Blank”. If the other line samples were moistened, moisten the blank swab by adding 2-3 drops of sterile water to the swab using a disposable Pasteur pipet. Add 2-3 drops of sterile DI water to the swab tube to ensure the swab stays moist during shipping.
- Interference check swab – Use one of the control swabs, mark it “Interference Check”. If routine sample is dry, use disposable Pasteur pipet to add 2-3 drops of sterile water to swab. Swab an area adjacent to an area where one of the routine sample swabs was taken. Do not swab an area that was already swabbed. Spike the swab by swabbing inside the spike solution vial (bottom, side and top) ensuring no liquid remains in the vial. Return the swab to its tube and add 2-3 drops of sterile DI water.
- Positive control – Use a second control swab, mark it “Positive Control”. If routine sample is dry, use disposable Pasteur pipet to add 2-3 drops of sterile water to positive control swab. Spike the swab by swabbing inside the spike solution vial (bottom, side and top) ensuring no liquid remains in the vial. Return the swab to its tube and add 2-3 drops of sterile DI water.
Shipping Instructions:
The swabs will need to be sent to the following address:
NQAC Dublin
6625 Eiterman Rd.
Dublin, OH 43016
To receive the most accurate results possible, ship the swabs within 24 hours of collection using ice packs to ensure that the swabs stay cold. There will need to be barrier between the swabs and ice packs to prevent freezing. Please be sure to include a submission form indicating which allergens will be tested.
If the swabs arrive above 25°C, they are considered compromised which can yield invalid results. If the swabs are received 72 hours after the swab collection date they will be considered as compromised. If there is missing or additional information needed to start the testing and the response is received after that 72-hour window the swabs will be considered as compromised