Used in immunohistochemistry and flow cytometry to detect Lewis Y antigen expression on epithelial cells and various carcinomas, particularly in breast, ovarian, and lung cancers. Helps in cancer research and diagnostic assays by identifying tumor-associated carbohydrate antigens. Also employed as a reference standard in antibody validation and assay development due to its well-characterized specificity. Supports studies on cell surface markers and glycosylation patterns in normal and malignant tissues.