iHaptenAb

iHaptenAb is a manually curated and publicly accessible database dedicated to hapten–antibody relationships for small-molecule targets. The current version contains 589 small-molecule targets, 1,678 immunizing haptens, 2,090 resultant antibodies and 6,718 immunoassay performance records, comprising 17,129 curated entries. The database systematically integrates chemical structures and properties of targets and haptens, hapten design and conjugation strategies, antibody affinity and specificity, and analytical performance of immunoassays. iHaptenAb organizes the data into seven interconnected entities—Target, Immunizing Hapten, Immunogen, Antibody, Coating Hapten, Coating Antigen and Evaluation—allowing users to trace the complete workflow from hapten design to antibody generation and immunoassay application. The database provides browsing, advanced Boolean and structure-based searching, interactive visualization, structural similarity analysis, physicochemical and quantum-chemical descriptors, and downloadable datasets. These integrated data facilitate the exploration of structure–property–performance relationships, rational hapten design, discovery of high-performance antibodies and machine-learning applications in hapten–antibody research.