Question

(a) Differentiate between- (i) Defined and Serum-supplemented medium (ii) Anchorage-dependent and Anchorage-independent cells (b) Explain how pH is maintained in animal cell cultures. Mention two advantages of maintaining pH during such cultures.

Answer 1

(a)

(i) Defined medium is a culture medium whose exact composition is known and precisely controlled, while serum-supplemented medium is a culture medium containing serum, which is a complex mixture of proteins and growth factors that can promote cell growth.

(ii) Anchorage-dependent cells are cells that require a surface or substrate to attach and grow, while anchorage-independent cells can grow in suspension without attachment to a surface.

(b)

The pH of the culture medium is an essential parameter for the growth and survival of animal cells in culture. It is usually maintained within a narrow range of 7.2-7.4 using buffering agents such as HEPES, MOPS, or CO2-bicarbonate system. The buffering system helps to stabilize the pH by neutralizing any changes in acidity or alkalinity.

Two advantages of maintaining pH during animal cell culture are:

• It ensures optimal enzyme activity and protein folding, which is crucial for maintaining the viability and functionality of cells in culture.
• It helps to maintain the stability of the culture environment, minimizing the risk of contamination and maintaining consistency in cell growth and function.