The extract from the heartwood is not a dye until it undergoes oxidation into hematein, which is an acid chromogen. |
The chromogen or pigmentary bacteria have occasionally been the means of working miracles. |
Urobilinogen reacts with a chromogen to form an azo dye which appears as various shades of pink or purple. |
A positive reaction is indicated if there is a colour reaction on the addition of chromogen and substrate. |
In other words, an auxochrome in addition to the chromophore group transforms a colorless chromogen into a colored one. |
Immunohistochemistry was performed on an automated immunostainer using the antibodies listed in Table 2 with diaminobenzidine as the chromogen. |