AlerTox Sticks Walnut
Product Reference: KIT3092
Website: www.hygiena.com
1. Intended Use
The AlerTox® Stick Walnut test kit is a rapid immunoassay lateral flow test kit for the qualitative detection of walnut antigens in food, kitchens, and production facilities. Test strips from AlerTox Sticks for almond, crustacean, fish, hazelnut, mustard seed, sesame, and walnut can be used to test samples prepared according to these instructions, but test kits from other AlerTox Sticks cannot be used. Read all instructions before starting the test.
2. Introduction
Walnut (Juglans regia) is a tree nut belonging to the Juglandaceae family. Walnut allergy is one of the most common tree nut allergies, with an estimated incidence of 0.1-1%. Walnut allergy can manifest in various symptoms, from mild oral allergy syndrome or urticaria to severe life-threatening systemic reactions such as anaphylactic shock or bronchial asthma. In the US, the Food Allergen Labeling and Consumer Protection Act (FALCPA) identifies tree nut allergy as one of the major food allergies, and packaging must indicate the presence of specific types of tree nuts. The European Food Safety Authority (EFSA) has established a list of allergens, including tree nuts, which must be declared in food according to Annex II of Regulation (EU) No 1169/2011.
3. Test Applications, Specificity, and Sensitivity
The AlerTox Stick Walnut test kit uses a monoclonal antibody combination against the major allergen of English/common walnut (i.e., the 11S globulin seed storage protein from Juglans regia, also known as allergen Jug r 4). The kit is suitable for the following applications:
- Food samples
- Rinse water testing
- Surface testing
The detection limit (LOD) for AlerTox Stick Walnut is 2.25 ppm walnut protein (2.25 mg walnut protein per kg or liter of sample). The range of detection (ROD) is 2.25 - 206,000 ppm walnut protein (mg/kg or mg/L). Overload (signal decrease) may occur in the range of 10,000 - 206,000 ppm; however, hook effect (false negative) will not occur in this range. For dried surfaces sampled with a moist swab, the LOD is approximately 4 micrograms of walnut protein per 16 cm² (2.5 in²). See the Certificate of Analysis for LOD (search by lot number, website: www.hygiena.com/documents). Section 12 lists the currently validated matrix list for the kit, with an LOD for walnut protein of 2.25 ppm.
4. Kit Contents
| Component | KIT3092 |
|---|---|
| Walnut immunoassay test strips in individual foil pouches | 10 |
| Sample collection tubes with yellow caps | 10 |
| Sample extraction buffer in tubes with blue caps, 10 mL | 10 |
| Spoons | 10 |
| Pipettes | 10 |
| 3 mL pipettes (for liquid sample testing only) | 10 |
| Swabs (for surface testing only) | 10 |
5. Other Materials Not Provided
- Grinder, mortar, or any other manual or automated homogenization system for sample pulverization.
- Vortex mixer/shaker (recommended, not mandatory).
- Scissors (for surface sampling only).
- Optional: Analytical balance (sensitivity of 0.1 g).
6. Precautions
- All components in the kit should be stored at temperatures between 10 to 30 °C (50 to 86 °F).
- After opening the foil pouch, use the test strip within 10 minutes.
- Do not touch the white end of the test strip.
- Do not use the test strip if it is damaged or the packaging is torn.
- Do not use the test strip after the expiration date.
- All kit components are single-use; do not reuse.
- Do not mix components from different kits.
7. Sample Handling
All samples must be brought to a temperature between 18 to 35 °C (64.4 to 95 °F) before use.
This test kit can detect target antigens in the following:
- Solid food
- Liquid samples: Beverages, rinse water from cutting equipment
- Surface swabs
8. Test Procedure for Solid Food Samples
8.1 Before adding the sample to the yellow-capped tube, grind or crush it to obtain the finest possible debris. Use a mortar or grinder if available.
8.2 Add 1 gram of sample to the yellow-capped tube. Alternatively, use the provided disposable spoon to add an equivalent amount of sample as per the table.
| Food Type | Sample | Spoon |
|---|---|---|
| Flour, fine powder | Corn flour, rice flour, milk powder, spices | 2 |
| Fine crumbs | Bread, biscuits, cakes, pastries | 2 |
| Meat, fish, and cured meats | Meat, fish, sausages, black pudding, pâté, canned meat and fish | 1 |
8.3 Pour the entire contents of the blue-capped tube (10 mL) into the yellow-capped tube. ? Important: Retain the blue cap for later use.
8.4 Cap the yellow-capped tube and shake the sample using a vortex mixer for at least 20 seconds to ensure sample homogenization. Alternatively, shake the tube vigorously by hand.
8.5 Let stand for 2 minutes to allow solids to settle.
8.6 Use a pipette to transfer the supernatant into the blue-capped tube. ? Note: For samples with high fat content, avoid the fatty layer in the supernatant.
8.7 Open the foil pouch, hold the blue end of the test strip, carefully remove the strip, and place the white end of the strip into the blue-capped tube. ? Note: Do not touch the white end of the test strip.
8.8 Wait 10 minutes to read the results. ? Note: Do not read the results after more than 10 minutes, as results may vary. Do not touch the test strip during this period.
9. Test Procedure for Liquid Samples
Liquid samples – beverages, rinse water from kitchen equipment, technical surfaces, or cutting machines – can be tested directly. Turbid samples should be filtered (paper or textile filter) or allowed to settle.
9.1 Using the provided 3 mL pipette, add 3 mL of liquid sample to the yellow-capped tube. If the sample is viscous (e.g., yogurt, sauce), add an equivalent amount of sample using the provided disposable spoon as per the table.
| Food Type | Example | Spoon |
|---|---|---|
| Liquids and sauces | Milk, fruit juice, condensed milk, yogurt, gravy, broth, sauce, cream | 3 |
? Note: Shake the sample to ensure homogeneity and that you are taking a representative portion of the test.
9.2 Add 3 mL of sample extraction buffer from the blue-capped tube to the sample using a 3 mL pipette. ? Important: Retain the blue cap for later use.
9.3 Cap the yellow-capped tube and shake the sample using a vortex mixer for at least 20 seconds to ensure sample homogeneity. Alternatively, shake the tube vigorously by hand.
9.4 If the liquid is turbid, let it stand for 2 minutes.
9.5 Use a pipette to transfer the supernatant into the blue-capped tube. ? Note: For samples with high fat content, avoid the fatty layer in the supernatant.
9.6 Open the foil pouch, hold the blue end of the test strip, carefully remove the strip, and place the blue end of the strip into the blue-capped tube. ? Note: Do not touch the white end of the test strip.
9.7 Wait 10 minutes to read the results. ? Note: Do not read the results after more than 10 minutes, as results may vary. Do not touch the test strip during this period.
10. Test Procedure for Surface Analysis
Collect each sample using a clean, unused swab. Swabs can be used for work surfaces or equipment.
10.1 Dip the swab into the blue-capped tube to moisten it. Then, rub the swab vigorously in a zig-zag pattern (at least 16 cm² / 2.5 in² or 40 cm² / 15.6 in²) over the surface to be tested. ? Note: Where possible, swab a square area of approximately 4 cm x 4 cm (1.6 in x 1.6 in). For irregular surfaces, ensure consistent swabbing technique for each test. The area chosen for analysis must be representative of the entire relevant area.
10.2 Place the swab into the sample collection tube and trim with scissors. ? Note: After capping, the swab should fit into the yellow-capped tube.
10.3 Pour the entire contents of the blue-capped tube (10 mL) into the yellow-capped tube. Then, press the swab tip against the inner wall of the yellow-capped tube to extract the sample into the buffer. ? Important: Retain the blue cap for later use.
10.4 Cap the yellow-capped tube and shake the sample using a vortex mixer for at least 20 seconds to ensure sample homogeneity. Alternatively, shake the tube vigorously by hand.
10.5 Use a pipette to transfer the supernatant into the blue-capped tube.
10.6 Open the foil pouch, hold the blue end of the test strip, carefully remove the strip, and place the blue end of the strip into the blue-capped tube. ? Note: Do not touch the white end of the test strip.
10.7 Wait 10 minutes to read the results. ? Note: Do not read the results after more than 10 minutes, as results may vary. Do not touch the test strip during this period.
11. Result Interpretation
If two colored lines appear: one in the control region (C) and another in the test region (T), the test result is "Positive". The intensity of the test line color may vary but is not necessarily proportional to the concentration of walnut antigen in the sample.
If only one clear colored line appears in the control region (C), the test result is "Negative".
If no colored line appears in the control region (C), the test is invalid.
If the test is invalid, check the following and repeat the test with a new test strip:
- Proper sample handling
- Correct test procedure
- Expiration date
- Correct storage conditions
For further assistance, contact Hygiena via www.hygiena.com/support.
? Important Note! AlerTox Sticks is a qualitative test for screening samples for internal quality control. Under no circumstances should it replace laboratory quantitative analysis.
12. Validation
AlerTox Sticks Walnut has been validated with the following matrices:
| Validated Matrix | Sample | Protein |
|---|---|---|
| Baked goods (including bread, breadsticks, biscuits, cakes, pastries) | Cereal and Cereal Snacks | Protein bar |
| Cheese | Dairy desserts (including ice cream) | Yogurt |
| Chocolate and chocolate bars | Nuts and nut beverages | Waffle |
Matrices must be validated before use with AlerTox Stick Walnut. For more information on matrix validation, contact Hygiena via www.hygiena.com/support.
13. Disclaimer
Intended Use: For use by technically qualified personnel under supervision for R&D, quality assurance, and quality control. Information generated by Hygiena products should only be used in conjunction with the user's routine quality assurance plan. Hygiena products should not be used as the sole basis for product safety assessment. Data obtained from Hygiena products must not be used for human diagnostic or therapeutic purposes. Before using the product, read the "Warranty and Limitation of Liability" (available from www.hygiena.com/terms-and-conditions).
These products are made from high-quality raw materials. Except for the quality of these materials, no warranty, express or implied, is made regarding their suitability, except when measuring target antigen levels when used strictly in accordance with these instructions.
Using the kit for any other purpose is beyond its intended use. For matrices not previously validated, Hygiena cannot guarantee the suitability of the kit or the accuracy of the results obtained on these matrices. Customers may choose to use the product on unvalidated food or surface matrices; however, Hygiena strongly recommends that users conduct their own validation tests to confirm suitability and performance in their specific application. Any loss, direct or indirect, arising from the use of this product, including consequential or special damages or expenses, is limited to the replacement value of the kit.
For additional information or assistance with matrix validation, contact Hygiena via www.hygiena.com/support. All Hygiena terms and conditions apply and can be found at: www.hygiena.com/terms-and-conditions.
14. Contact Information
For more information, visit www.hygiena.com/contact. For technical support, visit www.hygiena.com/support.
15. Change Index
- INS3027 REVB, September 2020: Includes more detailed information on English/common walnut and black walnut. Includes graphical workflow for liquid samples.
- INS-KIT3092-001-REVA, July 2025: Updated ROD. Standardized branding, wording, some graphical workflows, and document ID numbers.
Distributor Information (China)
Hai Jing Na (Shanghai) Trading Co., Ltd.
Address: Room 1202, No. 2218 Huangxing Road, Yangpu District, Shanghai (Shanghai Hesheng Hui)
Phone: 021-65060292
Email: contact@hygiena.com
WeChat Official Account: hygienachina
Manufacturer
Hygiena Diagnóstica España S.L.
P.I. Parque Plata, Calle Cañada Real 31 - 35, 41900, Camas (Sevilla), Spain
Website: www.hygiena.com
