mouse monoclonal IgG1; STEAP Antibody (B-4) is an IgG1 κ mouse monoclonal STEAP antibody (also designated STEAP antibody) that detects the STEAP protein of human origin by WB, IP, IF and ELISA. STEAP Antibody (B-4) is available as both the non-conjugated anti-STEAP antibody form, as well as multiple conjugated forms of anti-STEAP antibody, including agarose, HRP, PE, FITC and multiple Alexa Fluor® conjugates. Six-transmembrane epithelial antigen of the prostate (STEAP) is structurally similar to a channel or transport protein. STEAP protein contains six potential membrane-spanning regions with hydrophilic amino- and carboxyl-terminal domains. STEAP protein is present in human prostate tissue with elevated levels in cancer cell lines, including prostate, bladder, colon, ovarian, and Ewing sarcoma. Cell-cell junctions of the secretory epithelium show concentrated levels of STEAP protein. Mouse STEAP is 80% homologous to human STEAP at both the nucleotide and amino acid levels. The human STEAP gene maps to chromosome 7q21 and encodes a 339 amino acid protein.