Question

Chromosomes can be stained with ........... stain.

• A. Iodine
• B. Aniline blue
• C. Safranin
• D. Acetocarmine

Answer 1

Answer: (D)

Acetocarmine

Chromosomes can be stained with acetocarmine stain. Acetocarmine is formed from carmine and acetic acid. Carmine is a basic dye. It is prepared from an insect. To stain chromosomes, a 1% solution of carmine in 45% acetic acid is used. 1% acetocarmine is then use to stain chromosomes. When chromosomes are stained with acetocarmine, then two types of regions can be observed:

1. Heterochromatin region: This region gets dark stain during interphase. This is genetically inactive and highly condensed region with tightly packed DNA.
2. Euchromatin region: This region gets light stain during interphase. This portion is genetically active and rich in loosely packed DNA. Transcription occurs here.