Sulphhydryl and disulphide stainings of amyloid: a comparison with hyaline body

Histochemical staining for sulphhydryl (-SH) groups and disulphide (S-S) bonds was undertaken in 10 cases of cutaneous amyloidosis using the new fluorescent thiol reagent. A weak S-S fluorescence (but not -SH) was detected in dermal amyloid, suggesting that cross-linking of -SH groups may occur in amyloidogenesis. Since in normal skin S-S bonds were stained only in the horny layer and negligibly in the dermis, our findings seem to support the view that amyloid is derived at least partially from epidermal cells.