This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Death and postmortem changes, Subject name: Forensic Medicine
Stain used to stain X chromosome 
Select and explain. 
A. Quinacrine, B. Acriflavin Schiff reagent, C. Methylene blue, D. Fluorescent green
B: Acriflavin Schiff reagent
Answer: B: Acriflavin Schiff reagent 
Explanation: Barr body is formed due to random inactivation or condensation of one of the 2 female chromosomes in all the somatic cells of female mammals. Buccal smears are known to be potential source of Barr bodies. Acriflavin schiff stain was used in staining these Barr bodies. Ref: NCBI.org