Antigen staining can be caused by improper operation or by the quality of the kit itself.
When the antigen test is stained, first of all, it should be clear that the antigen test result is inaccurate and should be invalidated. There are two main reasons for antigen staining.
Improper operation leads to staining, which may be caused by the sample volume is too large. For example, in the New Crown Antigen Test Kit, dropping too much of the mixture of nasal swab and buffer on the antigen test card may lead to haloing. Pregnancy test strips may be caused by adding too many drops of urine.
In addition, problems with the quality of the antigen test kit itself may also cause staining, and when buffer is added to the test card, a large area of color development may occur. In both cases, the test result should be invalidated, and the test paper should be reused in accordance with the amount of reagent required for the operation.