Various tests are performed for the diagnosis of viruses and virus like organisms. These tests are classified into three categories namely the Biological assays, Serological assays and Molecular assays. Priority diseases are Citrus Tristeza Virus, Pepino Mosaic Virus, Tomato Yellow Leaf Curl Virus, Tomato Spotted Wilt Virus, Potato Spindle Tuber Viroid (PSTVd), Grapevine Flavescence Dorée and Plum Pox Virus. Identification is either done locally, or abroad, as necessary. Biological assays include mechanical transmission of viruses on specific herbaceous indicators. These are used for the confirmation of infection by quarantine pathogens. Serological assays involve mainly Double Antibody Sandwich - Enzyme Linked Immunosorbent Assay (DAS-ELISA) testing and Immunoprinting ELISA.  Molecular assays include the use of Reverse Transcriptase – Polymerase Chain Reaction (RT-PCR).​

 An ELISA plate showing positive samples