In order to perform immunostaining, tissue specimens should be fixed in appropriate fixative. The purpose of fixatives is to conserve tissue from autolysis, to preserve tissue structures, and to immobilize antigens. This requires harsh treatment of the antigens, resulting in chemical alteration of the antigen's secondary, and tertiary structures. Antigenic sites may be masked because of changes in the protein containing epitopes or in neighboring proteins. In the past, enzymatic treatment with proteolytic enzymes, i.e. pepsin, trypsin, or pronase, has been performed to regain masked antigens. Shi et al. (1991) have reported that treatment of the tissue sections with a heavy metal solution in a microwave can regain the masked antigens significantly. However, heavy metals in solution increases the risk of exposure of lab personnel to lead.
To solve this problem, we have developed a new antigen unmasking solution in tablet form which is free of heavy metals. Use of our Antigen Retrieval Tablets can prevent the risk of unnecessary exposure to heavy metals and also resolves handling and disposal problems.