DAS-ELISA commercial kits are available from several suppliers. Recently, serological tests based on the lateral flow technique have been developed that allow an easy and rapid diagnosis of SqMV in the fields. The ELISA is classified into homogeneous and heterogeneous depending on where the specific antigen–antibody interaction occurs. If all assay stages, including the enzymatic reaction proceed in solution, the ELISA format is homogeneous. To determine the target antigen or measure its quantity in a homogeneous assay, there is no need to separate the reacted and unreacted components. The heterogeneous format assumes separation of free and immunochemically bound labelled reagent (antigen, antibody) using a solid carrier with immobilized complementary reagent (antibody, antigen). At the same time, unbound components and unwanted inhibitory substances are eliminated from the reaction system by washing.