Question

Which stain is commonly used in study of cell division?
A. Feulgen reaction
B. Acetocarmine
C. Eosine
D. Safranin

Answer 1

Hint: M phase or mitotic phase is the phase where actual cell division occurs. It is the most dramatic period of the cell cycle. Prior to this, the cell duplicates its components and during this phase, the distribution of the already duplicated components occurs in an orderly manner. It consists of two processes.

Step by step answer:Cell division occurs in two processes:
Karyokinesis - where the division of the nucleus occurs
Cytokinesis - where the division of cytoplasm occurs.
The DNA is present in a tangled form during cell division. So, the stain that clearly shows the condensation of chromosomes during the prophase of mitosis.
-Feulgen reaction: It is discovered by Robert Feulgen. It is used to identify chromosomal material and DNA in a cell. It gives a dark stain. It is only used to stain DNA but it does not show condensation of chromosomes.
-Acetocarmine: It is a nuclear strain that binds with chromosomes so they show the ultrastructure of chromosomes thus shows condensation of chromosomes. It is a kind of dye that is extracted from insects.
-Eosine: Eosin is a fluorescent acidic compound that attaches to forms salts with basic, or eosinophilic, compounds that carry positive charges such as proteins that are positive because they contain amino acid residues such as arginine and lysine and stains them dark red or pink as a result of the actions of bromine on fluorescein.
-Safranin: It is used to detect gram-negative bacteria. It is a basic stain that is used to study histology and also cytology. It gives the nucleus a red colour.
Hence option B is correct.

Note: Mitogens are substances which induce mitosis e.g., Auxin, Cytokinin, Gibberellin, Insulin. All those substances or chemicals which inhibit mitosis or prevent the cells from entering into normal mitotic divisions are called mitotic poisons. The enzyme ribonuclease acts as poison at prophase.