Introduction

Histology, cytology and other related scientific disciplines study the microscopic anatomy of tissues and cells. In order to demonstrate a good tissue and cellular structure, the samples need to be stained in a correct manner. Fuchsin Basic-Schiff dye is used for DNA staining according to Feulgen and for PAS staining. PAS (periodic acid-Schiff) staining is one of the most commonly used staining methods used in histology. Using this method the material is treated with periodic acid, during which 1,2-glycols oxidate to aldehydes. During reaction with the Schiff reagent aldehydes turn bright red. The Feulgen reaction is based on mild hydrolysis of DNA molecules by using hydrochloric acid. Hydrolysis creates aldehyde groups that can be visualized with the Schiff reagent.