Amyloid precursor protein reduction

Antigen unmasking on sections of paraffin-embedded tissues can be accomplished by reduction of disulfide bonds by treatment with 2-mercaptoethanol, followed by alkylation with sodium iodoacetate to prevent the bonds from reforming. This method has been used for unmasking a Kunitz protease inhibitory domain epitope of Alzheimer s amyloid precursor protein in human brain (Campbell et al., 1999). Sections are reduced with a mixture of 0.14 M 2-mercaptoethanol in 0.5 M Tris-HCl (pH 8.0) and 1 mM EDTA for 3 hr in the dark at room temperature. After being washed for 3 min in distilled water, the sections are treated with a mixture of 250 mg/ml iodoacetic acid in 0.1 M NaOH, diluted 1 10 in 0.5 M Tris-HCl (pH 8.0) and 1 mM EDTA for 20 min in the dark. 

Jantzen PT, Connor KE, DiCarlo G, Wenk GL, Wallace JL, Rojiani AM, Coppola D, Morgan D, Gordon MN (2002) Microglial activation and beta -amyloid deposit reduction caused by a nitric oxide-releasing nonsteroidal anti-inflammatory drug in amyloid precursor protein plus presenilin-1 transgenic mice. J Neurosci 22 2246-2254. 

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