The oxidation products of Haematoxylin and their role in biological staining

On the mechanism of Mallory's phosphotungstic acid‐haematoxylin stain

“…Binding of haematoxylin is independent of pH up to pH 7; haematein requires acid dye baths and forms salts with amino groups (Dunkel, 1961). Marshall & Horobin (1972) Previous studies demonstrated that staining patterns of sequence iron haematein stains are determined by haematein, not Fe+++, and are virtually identical with those of consecutive haematoxylin-metal techniques (Puchtler & Sweat, 1964). In this study, the distribution of the blue colouration imparted by PTAH was identical with that of haematoxylin in sections aftertreated with PTA, FeCb or other suitable reagents.…”

Electrochemical oxidation of hematoxylin – Part 1: Experimental and theoretical studies in an aqueous acidic medium

“…The structure of hematoxylin (1) also has been confirmed by Marshal and Horobin in 1972 ( Fig. 1) [4]. It has been reported that the oxidation of hematoxylin (1) using oxidizing agents, converts it into hematein (1ox) [5,6].…”

“…Despite of the numerous reports on the chemistry and application of hematoxylin (1) and hematein (1ox) [1][2][3][4][5][6][7][8], a literature survey reveals that, a detailed study of the electrochemical behavior of hematoxylin (1) is missing and only a few reports have appeared on its electrochemical oxidation [9,10]. The importance of hematoxylin (1) on the one hand and the lack of electrochemical data, on the other hand, prompted us to investigate the electrochemical oxidation of hematoxylin (1) in the aqueous acidic solutions in the absence and presence of p-toluenesulfinic acid as a nucleophile using cyclic voltammetry, differential pulse voltammetry, controlled potential columetry and digital simulation methods.…”

Dyes and other colorants in microtechnique and biomedical research

“…Slow atmospheric oxidation of the remaining haematoxylin replaces haematein that is depleted by repeated use of the solution and by further oxidation. The main product of oxidation of haematein is a yellow compound known as oxyhaematein [48]. Haemalum is important because it imparts a strong blue colour to the nuclear chromatin of cells.…”