HT Histotechnician

Answer: D - All of the above

Schiff reagent can be prepared in different ways and these methods can be through Barger and Delamater, De Tomasi Coleman, as well as Hikawa and Oguru. All these methods utilize the same principle of sulfuration. This is to rearrange the chromophore group present in basic fuchsin. Therefore, all of the choices presented above are correct.