This chapter focuses on the Double Antibody Sandwich Enzyme-Linked Immunosorbent Assay (DAS-ELISA), a widely used technique for the detection and quantification of specific antigens, particularly in the context of plant virology and disease diagnostics. DAS-ELISA has the distinct ability to capture antigens using two distinct antibodies for enhanced specificity and sensitivity. The chapter outlines a detailed protocol highlighting the key factors that influence assay performance, such as antibody selection, incubation times, and washing protocols to optimize results. Troubleshooting strategies are also provided to address common challenges encountered during the assay. By the end of the chapter, readers will gain practical insights into the implementation and advantages of DAS-ELISA, making it a valuable tool for researchers and practitioners in the fields of plant pathology and diagnostics.