IHC antigen retrieval reagent (citrate, pH 8.0)

In order to perform immunostaining, tissue specimens should be preserved in an appropriate fixative. Fixation stops tissue autolysis, preserves tissue structures, and immobilizes antigens. However, antigens undergo chemical alteration of their primary, secondary and tertiary structures during fixation. Antigenic sites may be masked due to changes induced in the epitope or neighboring proteins. Enzymatic treatment with proteolytic enzymes (i.e. pepsin, trypsin or pronase) has been performed to expose the masked antigens. Shi et al. (1991) have reported that treating tissue sections with a heavy metal solution in a microwave oven can cover masked antigens significantly. However, heavy metals in the solution increase the risk of toxic exposure to lab personnel. To reduce the risk, we have developed an antigen unmasking solution which is free of heavy metals. The reagent is provided in a convenient 10X concentrate. Use of this antigen recovery buffer avoids unnecessary heavy metal exposure to lab personal and other handling and disposal issues. Interpretation of the results will be the sole responsibility of the user.