Food Allergen Lateral Flow IIR

Q&A regarding Food Allergen Lateral Flow IIR

Questions regarding performance

Q1. What can be detected by Lateral Flow IIR?
A1. Proteins derived from egg, milk, wheat, buckwheat and peanut can be detected.
Q2. How long does an assay take?
A2. It takes 30-60 minutes from the preparation to the determination,.
It is also possible to assay easier, depending on the subject and the sample.
Q3. Does the kit contain any agents regulated under Poisonous and Deleterious Substances Control Law and/or PRTR law?
A3. No agents regulated under the laws are contained.
Q4. What is the sensitivity of the kit?
A4. The kit shows positive when 25 ng/ml or more of total protein of specific raw material is in the test solution, which corresponds to 5 μg/g or more if converting into that of food.
Q5. Can you tell me about false-positive samples?
A5. Please refer to this for details of the false-positive samples.
Q6. Can you tell me about false-negative samples?
A6. As the reactivity between antigen and antibody in protein hydrolysates and similar products is changed, the assay may make underestimates rather than exact amounts. Please refer to this for details.

Questions of reagents and handling

Q7. Is it possible to use the sample extraction solution of Lateral Flow IIR in the series of Lateral Flow IIR in common?
A7. Yes. Solution A, B and C can be used commonly in the series of Lateral Flow IIR.
Q8. Is it possible to use dilute solution of Lateral Flow IIR in the series of Lateral Flow IIR in common?
A8. Yes. Solution D and E can be used commonly in the series of Lateral Flow IIR.
Q9. Can I use the extracted solution prepared with Food Allergen ELISA Kit series?
A9. No. The composition of the extracted solution with Lateral Flow IIR and of that with Food Allergen ELISA Kit series is different.
Q10. After opening the reagents, can I keep them for later use ?
A10. Although Solution A, B, C, D and E can be used until the expiration date described in the kit after opening them, please handle carefully enough not to contaminate the solutions with another agent at their opening and storage.
Test sticks are packed individually, so they can be opened just before use.
Q11. Can I keep the prepared sample extraction solution?
A11. The prepared sample extraction solution can be preserved for approximately 1 month at cool temperature or room temperature (20-30 °C). During preservation, please handle carefully to avoid contamination and similar accidents. Although white crystals can happen to appear during cool storage, they disappear after you return them to room temperature.
Q12. What can I do in cases of using less than 1 g of the sample? (in case of food inspection)
A12. In cases of using less than 1 g of the sample, extraction with 19 ml of extraction solution may lead to false negatives because of decreasing the antigen. Thus, in these cases, adjust the extraction solution volume appropriately so that the ratio of the sample and the extraction solution is 1:19.
Q13. Can I execute a swab test with a swab wetted with saline?
A13. Yes. But, it is impossible to test by dropping saline on a test stick.
Q14. On heating, is it better to loosen the lid of the tube?
A14. No. Be sure to tighten the lid of the tube, to avoid contamination during heating.
Q15. Can I omit or shorten the 10-minute heating period by bathing the tube in boiling water?
Can I shorten the time for the 10-minute heating with bathing in boiling water?
A15. No. To obtain correct test results, please execute 10-minute heating in boiling water.
Q16. Are there any problems when the heating time in boiling water is over 10 minutes?
A16. Yes. To obtain steady test data, the heating time must be 10 minutes.
Q17. How can I cool the reaction mixture in a tube?
A17. Immerse the tube in running water or a water bath or in a similar way to cool it slightly.
Q18. (In case of food inspection,) how do I handle samples for dilution followed by examination?
A18. After the filtrates are diluted with sample extraction solution appropriately, dilute them 10-fold with dilute solution for examination.
Q19. (In case of swab test,) how can I perform dilution followed by examination?
A19. After the heated solutions are diluted with sample extraction solution appropriately, dilute them 10-fold with dilute solution for examination.
Q20. Can I assay the solutions diluted in dilute solution in different ratios than 10-fold?
A20. No. You must use assay solution 10-fold diluted with dilute solution.
Q21. The site of the validation marker on a test stick removed from the pillow case is colored black. Is this possible to use?
A21. There are no problems with the product capability. A reagent is smeared on the site of the validation marker, so that in some cases it turns black.
Q22. I opened a pillow case and left it. Can I use it?
A22. Once a pillow case is opened, the test stick absorbs moisture so that depending on cases it affects the development of an assay solution. Accordingly, please avoid using the test stick after the time has passed since the pillow case is opened. Open a pillow case just before use of the test stick and use it immediately after opening.
Q23. How should I treat the test stick during reaction?
A23. Because of the possibility to affect the development of the assay solution, moving the test stick in reaction should be avoided. Place the test stick in reaction on a horizontal plane.
Q24. Any concerns for handling a test stick?
A24. Be sure to turn test sticks to room temperature (20-30 °C) before opening, and use immediately after opening. In addition, please make sure not to touch the dropping site and the determination site when you remove the test stick from a pillow case.

Questions of determination

Q25. I used a test stick without turning it to room temperature. Are there any effects on the result?
A25. Test sticks should be turned to room temperature (20-30 °C) before opening and the use. When you open a pillow case with lower temperature, the test stick absorbs moisture and it is hard to make the determination correctly in some cases. Furthermore, when the temperature during the reaction is lower than room temperature, the antigen-antibody reaction may be affected and in some cases the appearance of the line that shows the sample is positive may be delayed, so please take care regarding the reaction temperature.
Q26. The determination site as a whole in reaction is colored red. Are there no problems?
A26. There are no problems even the determination site as a whole is colored red in reaction. This is on a reaction process where assay solution and reagents are flowing. Do not make determination at this time. Leave as it goes and be sure to make determination after the specific reaction time.
Q27. Following the dropping of the assay solution, can I make determination in case of finding a line on the determination site before the end of the specific reaction time?
A27. Lateral Flow IIR is designed to make determination following the end of the specific reaction time of 15 minutes (for Lateral Flow IIR buckwheat, approximately 25 minutes). Although there are some cases of finding a line and the change of the validation marker, please be sure to make determination at the time that the specific reaction time has passed.
Q28. It has passed over the reaction time. Are there no problems to make determination?
A28. Lateral Flow IIR is designed to make determination after the reaction time of 15 minutes (for Lateral Flow IIR buckwheat, 25 minutes). Because of some cases that a correct determination results are hard to obtain in the condition over the reaction time, please be sure to make determination at the time the reaction time has passed.
Q29. The determination at the time the reaction time had passed was negative. After time had passed in addition, a line appeared on the determination site. How can I make determination about this?
A29. Lateral Flow IIR is designed to make determination after the reaction time of 15 minutes (for Lateral Flow IIR buckwheat, 25 minutes). Because the determination may change over time depending on samples, please be sure that the result at the time the reaction time has passed is judged as the determination result. Even in such case of having found a line on the determination site over time, the determination is negative when the reaction time has passed, so that please handle the determination result as negative.
Q30. Are there any factors to affect the assay result?
A30. Two factors as follows are possible to affect the assay result adversely:
extreme acidity and basicity, ionicity (strength and type), viscosity, protein hydrolase, surfactant, oxidation, alcohol and similar agents may affect the assay result;
a highly colorable sample may be difficult to validate a clear band.

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