Fluorescent feulgen reaction is used to demonstrate

The X chromosome is seen as a Plano convex mass lying inside the nucleus just beneath the nuclear membrane as a nucleolar satellite, in the cells of buccal mucosa. This is called Barr body. Barr bodies are seen in the somatic cells of normal females (XX) Barr bodies can be demonstrated by eosin- hematoxylin staining or fluorescent Feulgen reaction technique using Acriflavine Schiff reagent for X chromosome which is seen as a bright yellow spot. Ref: FORENSIC MEDICINE AND TOXICOLOGY Dr PC IGNATIUS THIRD EDITION PAGE 70