Why are there so many oranges on the parallel bars?

There are so many orange parallel bars because it will destroy the pH value of antigen detection reagents. The origin of this problem is that someone dropped orange liquid on the antigen test paper, and the parallel bars appeared as a result. Any liquid of different substances will react to the test paper, and orange juice will destroy the pH value of antigen detection reagent, leading to the phenomenon of two strips in antigen detection.