Tips on Food Allergen Test Methods
ATP quick tests may be useful in assessing the cleanliness of surfaces; however, these kits do not directly measure allergenic proteins or pathogens. ELISA based methods are developed specifically to determine the presence of specific allergenic food proteins. Each assay targets a certain allergenic protein or class of proteins specific to an allergenic food, with limited cross reactivity to other food proteins. For example, an ELISA that targets the milk protein, Casein (milk solids), will not detect another milk allergen, such as Beta-lacto-globulin (whey protein). Additionally, when target proteins (such as egg or gluten) are denatured due to heat treatment (baking, frying, or pasteurization) or fermentation, ELISA-based methods may not detect them properly, so it is necessary to select kits that are appropriate for the matrix at hand. Likewise, certain sample types may give false negative results when using ELISA-based methods. In such cases, DNA-based methods may be appropriate. Finally, ELISA methods do not exist for some allergenic proteins, but PCR can provide an alternate, source-specific detection method in these situations.
Choosing Your Swab Type
Collecting environmental samples in an aseptic manner is critical to ensuring the quality of the testing results. If the person collecting the samples contaminates the specimen, the laboratory results will not accurately reflect the condition of your manufacturing environment. In addition, they type of swab you use, matters. There are multiple commercial sampling tools available for use. Your best tool is to source sterile and dry swabs resembling a Q-tip stored in individual plastic coverings.
Swabs to not use:
How to Sample
1. Collect swabs needed. One swab is used per test. For example, if needing gluten and milk allergen tests, you will need 2 swabs per sampling area. If sending in for our tree nut or full allergen package, please note you will need a swab for each individual allergen screened.
2. Label each swab unit. If your swabs did not come in individual plastic containers, you may place swabs in sterile plastic bags after a sample is collected. One bag per swab. Make sure the sample number matches the sample number on your Sample or Order Form.
3. Wash, dry, and sanitize hands.
4. Aseptically glove hands.
5. Aseptically remove swab from its container.
6. Prepare your swab.
o For dry surfaces: aseptically, moisten your swab before sampling with distilled or HPLC-grade water.
o For wet surfaces: no distilled or HPLC-grade water is needed. Proceed with swabbing.
7. Thoroughly swab your designated area using a steady pressure.
8. Add swab back to individual container or plastic bag.
9. Sanitize sampling site.
10. Wash hands and replace gloves between sampling sites.
11. Within 24 hours, send samples to the laboratory in a clean container with ice packs such that sample temperature does not exceed 45°F.
Tracking Records
Keeping accurate up-to-date records is important for the success of any environmental monitoring plan. Good record keeping can help provide the necessary information on which decisions regarding future allergen monitoring can be based. A log book or spreadsheet could be used to track these key areas.
Choosing Your Swab Type
Collecting environmental samples in an aseptic manner is critical to ensuring the quality of the testing results. If the person collecting the samples contaminates the specimen, the laboratory results will not accurately reflect the condition of your manufacturing environment. In addition, they type of swab you use, matters. There are multiple commercial sampling tools available for use. Your best tool is to source sterile and dry swabs resembling a Q-tip stored in individual plastic coverings.
Swabs to not use:
- Sponges or sponge sticks
- Any swab soaked in a buffer solution
- Swabs used for microbiology environmental monitoring
How to Sample
1. Collect swabs needed. One swab is used per test. For example, if needing gluten and milk allergen tests, you will need 2 swabs per sampling area. If sending in for our tree nut or full allergen package, please note you will need a swab for each individual allergen screened.
2. Label each swab unit. If your swabs did not come in individual plastic containers, you may place swabs in sterile plastic bags after a sample is collected. One bag per swab. Make sure the sample number matches the sample number on your Sample or Order Form.
3. Wash, dry, and sanitize hands.
4. Aseptically glove hands.
5. Aseptically remove swab from its container.
6. Prepare your swab.
o For dry surfaces: aseptically, moisten your swab before sampling with distilled or HPLC-grade water.
o For wet surfaces: no distilled or HPLC-grade water is needed. Proceed with swabbing.
7. Thoroughly swab your designated area using a steady pressure.
8. Add swab back to individual container or plastic bag.
9. Sanitize sampling site.
10. Wash hands and replace gloves between sampling sites.
11. Within 24 hours, send samples to the laboratory in a clean container with ice packs such that sample temperature does not exceed 45°F.
Tracking Records
Keeping accurate up-to-date records is important for the success of any environmental monitoring plan. Good record keeping can help provide the necessary information on which decisions regarding future allergen monitoring can be based. A log book or spreadsheet could be used to track these key areas.
- Date and Time of Sampling
- Name of Person Collecting Sample
- Sample Locations
- Date Submitted to Laboratory
- Results
- Corrective Actions if Needed