The Reveal 3-D format is a single-step lateral flow immunochromatographic assay. The extract is wicked through a reagent zone, which con­tains antibodies specific for the target allergen conjugated to colored particles. If allergen is present, it will be captured by the conjugated antibodies. The allergen antibody-particle complex then is wicked onto a membrane which contains a zone of antibody specific for the target allergen. This zone captures the complex allowing the particles to concentrate and form a visible line. If no target allergen is present, no line will form.