Anti-3OST4 antibodies are used in antigen-specific immunodetection in biological samples. The target 3OST4 is a known alias name of the protein heparan sulfate-glucosamine 3-sulfotransferase 4, encoded by the HS3ST4 gene in humans. This 456-amino acid residue protein is a reported sulfotransferase that utilizes 3'-phospho-5'-adenylyl sulfate (PAPS) to catalyze the transfer of a sulfo group to an N-unsubstituted glucosamine linked to a 2-O-sulfo iduronic acid unit on heparan sulfate. It is localized to the Golgi of the cell and features glycosylated post-translational modifications. In terms of tissue expression, it is reported to have brain-specific expression.