The immunoalkaline phosphatase technique in immunohistochemistry: the effect of permanganate-oxalate melanin bleaching upon four final reaction products.

Melanin bleaching prior to the application of primary antibody can alter the immunoreactivity of a number of antigens. The effect of melanin bleaching subsequent to antigen visualisation by four different chromogens used with an immunoalkaline phosphatase technique was investigated. Vector black was the only final reaction product that withstood exposure to the permanganate-oxalate sequence for a time sufficient to bleach melanin.