Use of Ethylenediaminetetraacetic Acid EDTA for Antigen Retrieval

Another recent study also supports the mediation role of EDTA in unmasking antigens (Rocken and Roessner, 1999). In this study thin sections of aldehyde-fixed, Epon-embedded human biopsy tissues were treated with 1 mM EDTA, using a heated water bath. This combined treatment resulted in excellent immunogold staining of amyloid (Fig. 6.4). 

Because heating in water alone did not improve immunostaining, it is concluded that epitope retrieval is mediated not only by heat and rehydration but also by the presence of a chelating agent such as EDTA. However, caution is warranted in using EDTA, which may adversely affect cell morphology because it is a strong oxidant. 

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