Question

Which substance is used to keep cells in the metaphase stage of mitosis in blood culture technique?
(a) Cholecystokinin
(b) Chitin
(c) Colchicine
(d) Phyto Hemoglobin

Answer 1

The substance required for arresting cells in the metaphase stage of mitosis is a commonly used substance in cell culture. The substance interferes with the formation of a mitotic spindle and thus arresting the cell in the phase.

Complete step by step answer:
The substance used to keep cells in the metaphase stage of mitosis in blood culture is colchicine.
- Colchicine interferes with cell division by inhibiting the formation of a mitotic spindle.
- In routine karyotyping procedure from blood culture or lymphocyte culture, cells are exposed to colchicine to arrest cell division at metaphase to visualise chromosomes or even isolate them.
- Colchicine is also used as a medicinal drug for the treatment of gout and joint swelling. It is also used as an anti-inflammatory agent.

Additional Information:
Cholecystokinin is a peptide hormone secreted in the small intestine and is responsible for stimulating the digestion of fat and protein.
- Chitin is a long chain polymer of N-acetylglucosamine. It is well-known to be a component of cell walls of fungi and exoskeleton of arthropods.
- Phytoglobin are globular plant proteins belonging to the globin family. An example is leghemoglobin, an oxygen-carrying phytoglobin found in the nitrogen-fixing root nodules of leguminous plants.

So, the correct answer is ‘(c) Colchicine’.

Note:
Colchicine is used to isolate mitotic chromosomes from cell cultures using monolayer cultures as well as cell suspensions.
- Blood cultures are required to detect the presence of microorganisms in blood as they are indicative of a blood infection such as meningitis and sepsis.