Question 1

What is animal cell culture?

Accepted Answer

Animal cell culture is the process of growing animal cells in a controlled artificial environment outside the organism. It involves isolating cells from animal tissues and providing them with suitable nutrients, growth factors, and conditions to survive and multiply in vitro. — Animal cells are taken from tissues and grown in nutrient media under sterile conditions. This allows study and manipulation of cells for research, vaccine production, and biotechnology applications.

Question 2

Describe animal cell culture media and their types.

Accepted Answer

Animal cell culture media are nutrient solutions used to support the growth and maintenance of animal cells in vitro. They provide essential nutrients such as amino acids, vitamins, minerals, glucose, and growth factors. Types of culture media include:

1. Natural media: Contain serum or extracts from animal tissues.
2. Synthetic or chemically defined media: Composed of known quantities of pure chemicals without serum.
3. Serum-free media: Media formulated without serum but supplemented with necessary growth factors.

Each type is chosen based on the cell type and experimental requirements. — Media provide the necessary environment for cell survival and proliferation. Serum contains growth factors but has variability, so chemically defined media are preferred for reproducibility.

Question 3

Write the advantages and disadvantages of serum in the culture media.

Accepted Answer

Advantages of serum:
- Provides growth factors and hormones essential for cell proliferation.
- Enhances cell attachment and spreading.
- Acts as a source of transport proteins and binding proteins.

Disadvantages of serum:
- Batch-to-batch variability affects reproducibility.
- Risk of contamination with viruses or prions.
- Expensive and ethical concerns regarding animal use.
- Difficult to define exact composition, complicating experimental analysis. — Serum supports cell growth but introduces variability and risks, so alternatives like serum-free media are developed.

Question 4

Describe any two chemically synthesised media.

Accepted Answer

Two chemically synthesised media are:

1. RPMI-1640 Media: Contains amino acids, vitamins, inorganic salts, glucose, and buffering agents. It is widely used for culturing lymphoid cells.

2. DMEM (Dulbecco's Modified Eagle Medium): A modification of Eagle's medium with higher concentrations of amino acids and vitamins, supporting a wide variety of cell types.

These media are chemically defined and do not contain serum, allowing controlled studies. — Chemically synthesised media provide known compositions, reducing variability and allowing specific nutrient requirements to be studied.

Question 5

What is primary cell culture? Also discuss as to how it is developed.

Accepted Answer

Primary cell culture is the culture of cells directly taken from animal tissues and maintained in vitro. It represents the first generation of cells cultured from the tissue.

Development of primary culture involves:
- Isolation of tissue from an animal.
- Disaggregation of tissue into single cells by mechanical or enzymatic methods.
- Seeding the cells into culture vessels containing suitable culture media.
- Incubation under controlled conditions to allow cells to attach and proliferate.

Primary cultures have a limited lifespan and closely resemble the in vivo state of cells. — Primary cultures are important for studying normal cell physiology but have limited division potential.

Question 6

What is subculture or passaging of cells?

Accepted Answer

Subculture or passaging is the process of transferring cells from a crowded culture vessel to a fresh culture vessel with new growth medium to provide more space and nutrients for continued growth. — As cells proliferate, they exhaust nutrients and space; passaging prevents overconfluence and maintains healthy growth.

Question 7

Differentiate between finite and continuous cell lines.

Accepted Answer

Finite cell lines:
- Derived from primary cultures.
- Have a limited lifespan and undergo a fixed number of cell divisions.
- Eventually undergo senescence and die.

Continuous cell lines:
- Derived from transformed or cancerous cells.
- Can divide indefinitely and are immortal.
- Used extensively in research due to their unlimited growth potential. — Finite lines mimic normal cells but have limited use; continuous lines are immortal but may differ from normal physiology.

Question 8

How is cell viability measurement performed?

Accepted Answer

Cell viability is commonly measured using assays such as the MTT assay, Trypan blue exclusion test, or dye exclusion methods. For example, in the MTT assay, viable cells reduce MTT to a purple formazan product, which can be quantified spectrophotometrically to estimate the number of living cells. — Viability assays distinguish live cells from dead cells based on metabolic activity or membrane integrity.

Question 9

Write a detailed account of application of cell culture.

Accepted Answer

Applications of animal cell culture include:
- Production of vaccines and therapeutic proteins.
- Study of cell biology, genetics, and biochemistry.
- Toxicity testing of drugs and chemicals.
- Cancer research and development of anticancer drugs.
- Genetic engineering and gene therapy research.
- Molecular pharming to produce proteins in transgenic animals.
- Regenerative medicine and tissue engineering.

Cell culture provides a controlled environment for detailed studies and biotechnological applications. — Cell culture is a versatile tool in research and industry, enabling advances in medicine and biology.

Question 10

The example of animal cell culture media is:
(a) DMEM
(b) MS media
(c) LB Media
(d) All of the above

Accepted Answer

DMEM — DMEM (Dulbecco's Modified Eagle Medium) is a commonly used animal cell culture medium. MS media is used for plant tissue culture, and LB media is used for bacterial culture. Hence, only DMEM is an animal cell culture medium.

Question 11

Name the type of culture that is prepared by inoculating directly from the tissue of an organism to culture media.
(a) Primary cell culture
(b) Secondary cell culture
(c) Cell lines
(d) Transformed cell culture

Accepted Answer

Primary cell culture — Primary cell culture is prepared by directly inoculating cells from animal tissue into culture media. Secondary cultures are subcultures derived from primary cultures. Cell lines and transformed cultures are established from continuous or immortalized cells.

Question 12

Sodium bicarbonate is added to animal cell culture media to
(a) keep cells stuck to the plastic
(b) promote the uptake of CO2 into animal cells
(c) maintain the correct pH when CO2 is present
(d) keep iron soluble

Accepted Answer

maintain the correct pH when CO2 is present — Sodium bicarbonate acts as a buffer in culture media to maintain pH stability in the presence of CO2 in the incubator atmosphere.

Question 13

Which of the following is NOT present in growth medium for animal cell culture?
(a) Inorganic salts
(b) Bicarbonate
(c) Carbon source
(d) Starch

Accepted Answer

Starch — Starch is not a component of animal cell culture media. Animal cell culture media contain inorganic salts, bicarbonate as buffer, and carbon sources like glucose.

Question 14

Disaggregating of cells can be performed by:
(a) Physical disruption
(b) Enzymatic digestion
(c) Treating with chelating agents
(d) All of the above

Accepted Answer

All of the above — Cells can be disaggregated by physical methods (mechanical disruption), enzymatic digestion (e.g., trypsin), and chelating agents (e.g., EDTA) that remove calcium ions to separate cells.

Question 15

The approach in which genes are transferred into animals to obtain a large scale production of the proteins encoded by these genes in the milk, blood, etc., is called
(a) In situ culture
(b) Molecular pharming
(c) Gene therapy
(d) Hybridoma technology

Accepted Answer

Molecular pharming — Molecular pharming involves genetically modifying animals to produce therapeutic proteins in milk, blood, or other secretions for large-scale production.

Animal Cell Culture

Animal Cell Culture — Study Notes

Animal Cell Culture

8.1 Historical Perspective

8.2 Culture Media

Practice Questions — Animal Cell Culture

All 13 Chapters in Biotechnology