The BCAP31 (B-cell receptor-associated protein 31) antibody is a tool used to detect the BCAP31 protein, a ubiquitously expressed transmembrane protein located in the endoplasmic reticulum (ER). BCAP31 plays critical roles in ER-associated degradation (ERAD), vesicular trafficking, and apoptosis regulation. It interacts with various proteins, including B-cell receptors, caspase-8. and presenilin-1. and is implicated in maintaining ER homeostasis, modulating immune responses, and facilitating protein transport between the ER and Golgi apparatus. Dysregulation of BCAP31 has been linked to cancers, neurodegenerative disorders (e.g., Alzheimer’s disease), and X-linked intellectual disability syndromes (e.g., CMTX5/HSMN5). Researchers employ BCAP31 antibodies in techniques like Western blotting, immunofluorescence, and immunoprecipitation to study its expression, subcellular localization, and interactions. These antibodies, often raised in rabbits or mice, are validated for specificity using knockout cell lines or siRNA knockdown. BCAP31 antibodies are essential for exploring its role in cellular stress responses, apoptosis signaling, and pathological mechanisms, aiding advancements in cancer biology, neurobiology, and genetic disorder research.