Question

Which dye is used to stain the chromosome?
a) Acetocarmine
b) Haematoxylin
c)Feulgen
d)All of the above

Answer 1

Hint: The chromosome is the thread-like structures present in the nucleus of the cell. A chromosome is made up of proteins and a single unit of DNA. It is a hereditary material that is passed on from generation to the generation from parents to the offspring.

Complete answer:
The stain used for dying the chromosome is acetocarmine. This stain is a DNA-specific stain and is used when the study of different mitotic stages is required. To stain chromosomes first acetocarmine dye is prepared using the carmine. Carmine is a basic dye which is obtained from the offspring insect. The solution of acetocarmine is prepared by mixing carmine with glacial acetic acid. The bottle is kept in the dark and is stored at a low temperature. Freshly prepared sample is taken and is stained using the dye prepared. Usually, the dye needs to be kept for half an hour or more depending on the sample taken. If the material fixation time was long then the staining time is also longer. Hematoxylin is the basic dye and it is used for dying the acidic substances. It also helps in the staining of RNA and DNA as they are acidic in nature. They impart a characteristic dark blue or purple color. Feulgen dye is the aldehyde specific reactive dye that stains when a reaction of aldehydes occurs with the fuchsin-sulphuric acid. It gives a characteristic colour of purple.
So, the answer is ‘all of the above’.

Note: Feulgen stain was developed by Robert Feulgen. This dye uses acid hydrolysis of DNA for staining. Haematoxylin stain is also used for the tissue staining and is very helpful in the field of medical diagnosis.