1EJH_2019_04_original.qxp_Hrev_master 31/10/19 09:47 Pagina 214 European Journal of Histochemistry 2019; volume 63:3071 Bleaching melanin in formalin- different and partly unknown molecular fixed and paraffin-embedded features. In general, melanins can be Correspondence: Claudio Pigoli, Department defined as a heterogeneous group of mole- of Veterinary Medicine, University of Milan, melanoma specimens using cules deriving from the oxidation of pheno- Via dell'Università 6, 26900 Lodi, Italy. visible light: A pilot study lic compounds with polymerization of the Tel. +39.02.50334165. resulting chemical products. In animals, E-mail:
[email protected] 1 2 melanins are subdivided into eumelanins, Claudio Pigoli, Lucia Rita Gibelli, Key words: Bright-field microscopy; canine; 1 3 black to brown in color, and pheomelanins, Mario Caniatti, Luca Moretti, 1 equine; feline; light radiation; photobleaching; 1 1 reddish to yellowish. A third subtype of swine. Giuseppe Sironi, Chiara Giudice melanin, called neuromelanin and often 1Department of Veterinary Medicine, associated to the afore-mentioned groups, is Contributions: CP, LRG, MC, LM, GS, CG, University of Milan, Lodi composed of a mixture of eumelanins and study design, data analysis and interpretation; 2Istituto Zooprofilattico Sperimentale pheomelanins. In particular, it has been LM, performing of the light source spectral measurement; CP, performing of the photo- della Lombardia e dell’Emilia Romagna, hypothesized that neuromelanin granules consist of a pheomelanin core surrounded bleaching protocol, histochemical and Milan 2 immunohistochemical stains; CP, LRG, MC, 3 by a eumelanin layer. Department of Physics, Politecnico di GS, CG, viewed the histological specimens. In animals, melanin granules are pres- Milano, Milan, Italy All the authors have drafted the manuscript ent in various sites including integumentary and reviewed the work critically, have read system, eye, central nervous system and and approved the final manuscript and agreed inner ear.