Question

One of the following dyes cannot be used for staining chromatin material.

• A. Acetocarmine
• B. Crystal violet
• C. Haematoxylin
• D. Schiffs reagent (Feulgen stain)

Answer 1

The correct option is B Crystal violet

Crystal violet is the stain used in Gram's staining procedure. Acetocarmine or Orcein is used for nuclei and chromosomes staining. It is a pink dye. Feulgen or Schiff's reagent was developed by Feulgen and Rossenbeck to stain DNA. Basic dyes stain chromosomes and other nuclear structures.

Exapmple : Hematoxylin is a basic / positive compound that binds to and forms salts with acidic, or basophilic, compounds containing negative charges (such as DNA and RNA) and stains them dark blue or violet.