What is the Hook Effect?

A high dose hook effect refers to a false negative result when the amount of target allergen exceeds the amount of colour-labelled antibody material present in the reagent pad. Occurs when excess target allergen migrates across the membrane quicker than the colour-labelled antibody-antigen complex and saturates the binding sites at the test line. When the colour-labelled complex arrives, there are no binding sites remaining, so it continues to travel up the membrane to the waste reservoir at the end of the device. Since no binding sites are available, the colour-labelled antibody-antigen complex cannot create the coloured test line that indicates a positive result. This presents the user with a false negative result, despite high levels of the target allergen.