Effect of Endogenous Calcium on Antigen Masking

Based on this observation, calcium released from this complex requires high-temperature heating in combination with a calcium chelating and/or precipitating agent such as EDTA, EGTA, citrate buffer, or urea. Because these reagents are chelators of divalent 

A somewhat different interpretation of the relationship of aldehyde fixation with the masking of antigens with calcium-protein complexes is reported by Shi et al. (1999a). According to this point of view, although calcium-induced modification of the protein molecule does occur and can be demonstrated immunohistochemically, it is independent of formalin-induced crosslinking. Addition of calcium chloride can reduce or alter immunostaining, but it is not related to the pH of this solution. 

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