It recognizes a protein of HMW, identified as mucin 3 glycoprotein (MUC3). Its epitope localizes between amino acids SITTTE. This mAb shows no cross-reaction with human milk fat globule membranes, MUC1, or MUC2. MUC3 is distributed in colon and rectum, and is also present to a lesser extent in breast, lung and salivary gland tissues. The Mucins are a family of highly glycosylated, secreted proteins with a basic structure consisting of a variable number of tandem repeats (VNTRs) encoded by 60 base pairs (Mucin 1), 69 base pairs (Mucin 2) and 51 base pairs (Mucin 3). The number of repeats is highly polymorphic and varies among different alleles. Mucin 1 proteins are expressed as type I membrane proteins in addition to secreted forms. Mucin 1 is aberrantly expressed in epithelial tumors including breast carcinomas. Mucin 2 coats the epithelia of the intestines and airways and is associated with colonic tumors. Mucin 3 is a major component of various mucus gels and is broadly expressed in normal and tumor cells.

Optimal dilution of the Mucin-3 antibody should be determined by the researcher.

1. Staining of formalin-fixed tissues requires boiling tissue sections in 10mM Tris with 1mM EDTA, pH 9.0, for 10-20 min followed by cooling at RT for 20 minutes2. The prediluted format is supplied in a dropper bottle and is optimized for use in IHC. After epitope retrieval step (if required), drip mAb solution onto the tissue section and incubate at RT for 30 min.

Amino acids (C-HSTPSFTSSITTTETTSHSTPSFTSSITTTETTS) which contains two of the MUC3 tandem repeats was used as the immunogen for the Mucin-3 antibody.

Store the Mucin-3 antibody at 2-8oC (with azide) or aliquot and store at -20oC or colder (without azide).