Food Allergen Lateral Flow

Lateral Flow IIR - Troubleshooting

1. A determination line is hard to be found in case of using a sample with a specific raw material concentration high.

In case of containing the subject protein in extremely higher concentration, a line does not appear even the validation marker is colored (prozone phenomenon). If you wish to assay such a sample, dilute the sample appropriately to re-assay.
* According to samples, the procedures of diluting manipulation are different. In case of food inspection: after the filtrates are diluted with sample extraction solution appropriately, dilute them in 10-fold with dilution solution for examination.
In case of smear test: after the heat treated solutions are diluted with sample extraction solution appropriately, dilute them in 10-fold with dilution solution for examination.

2. The validation marker is not colored red at 15 minutes (for Lateral Flow IIR buckwheat, 25 minutes) after dropping the assay solution.

Because of not enough to develop the assay solution, additional dilution is recommended for re-assay.
* According to samples, the procedures of diluting manipulation are different.
In case of food inspection: after the filtrates are diluted with sample extraction solution appropriately, dilute them in 10-fold with dilution solution for examination
In case of smear test: after the heat treated solutions are diluted with sample extraction solution appropriately, dilute them in 10-fold with dilution solution for examination.

3. The sample that is considered as being possible to dissolve in sample extraction solution, such as thickened polysaccharides, is hard to dissolve thoroughly.

Because the sample does not dissolve in extraction solution as a whole, reduce the sample volume to make dissolved at the extraction for examination. However, because the dilution rate at the extraction is changed, the detection sensitivity converted to the value in case of food sample is to change.
Example: in case of “extracting 0.5 g of a sample with 19.5 ml of extraction solution (40-fold extraction)” instead of the manipulation of “extracting 1 g of the sample with 19 ml of extraction solution (20-fold extraction),” the detection sensitivity on the stick is 25 ng/ml, which does not change, but the detection sensitivity converted to the value in case of food sample changes from 5 μg/g to 10 μg/g.

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