Question

Which dye is used to stain chromosomes?

• A. Acetocarmine
• B. Haematoxylin
• C. Feulgen
• D. All of the above

Answer 1

The correct option is D All of the above

Acetocarmine is a saturated solution of carmine in 45% acetic acid used especially for the rapid staining of fresh unfixed chromosomes. It is used to study the stages of cell division.

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 which are acidic/negative because the nucleic acid building blocks that come off the phosphate backbone are negatively charged and stains them dark blue or violet.

Feulgen technique is an aldehyde specific reaction based on the formation of a purple-colored compound when aldehydes react with fuchsin-sulfuric acid. Deoxyribonucleic acid gives this reaction after removal of its purine bases by acid hydrolysis. It means for the histochemical detection of deoxyribonucleic acid (DNA) in animal and plant cells, as well as in bacteria. It was proposed in 1924 by the German chemist R. Feulgen.