The“mercury-affinity reaction”which is thought to demonstrate unsaturated C-C bonds of ceroid on formalin-fixed paraffin sections has been found to react heavily with the zymogen granules of the pancreatic exocrine portion, the striate portion as well as the serous cells of the parotid gland, the stratum corneum of the skin, the external root sheath of the hair cortex, nucleus of the hypothalamus, neurosecretory substances of the infundibulum hypothalamium and α cells (partially βcells) of the anterior pituitary.
On the other hands, these tissue elements reveal a positive finding with the Maeda et al. colloidal iron hydroxide method for sulfhydryl and disulfide groups with or without the pretreatment of thioglycollic acid.
Thereupon, the authors examined whether or not divalent mercury used in the“mercuryaffinity reaction”, would combine with sulfhydryl group, besides unsaturated C-C bonds, because there are a few test methods principle of which is based on a mercaptide formation of sulfhydryl group. Consequently, it was found that the degree of a positive coloring of the“mercury-affinity reaction”was considerably lowered by the pretreatment with thioglycollic acid and was not influenced by N-ethylmaleimide blocking for sulfhydryl group, these findings being contrary to those obtained by the colloidal iron hydroxide method.
In view of the above results, it is concluded that the“mercury-affinity reaction”does not react with sulfhydryl or disulfide groups, its specificity for unsaturated C-C bonds being approved enough.
