This document provides a comprehensive overview of cell lines, encompassing definitions, types, characteristics, requirements, and applications in research. Key information includes the development of cell culture techniques, commonly used cell lines like HeLa and HEK 293, and their importance in drug testing, vaccine production, and genetic studies. It also highlights limitations such as genetic instability and ethical concerns, emphasizing the need for careful experimental design in cell line research.

1. By Krishna Chavda
Unit : 4 - Cell Lines
SUBJECT : 401
COURSE : Zoology GIA
Roll no. : 4
To : Dr. Divya Chandel

2. Index
1. Cell Culture
2. Cell lines
3. Features of cell lines
4. Characteristics of cell lines
5. Requirements of cell lines
6. Types of cell lines
7. Commonly used cell lines
8. Uses of cell lines
9. Applications of cell lines
10. Limitations of cell lines
11. Questions
12. References

3.  Cell Culture :
 What is cell ?
• Cells are the basic building blocks of all living things.This complex system is the
command for your body.
 Cell culture :
• Cell culture is the multifaceted process through which cells are isolated from
animal or plant and their subsequent growth under controlled artificial
conditions, generally outside their natural environment.
• In this procedure cells are directly isolated from body or disaggregated by
enzymatic or mechanical procedure or they may be derived from cell lines or cell
strains.
• The historical development and methods of cell culture are closely interrelated
to those of tissue culture and organ culture.
• The in vitro propagation of cells has become a common practice in many
laboratories for a huge numbers of applications.
• The ranges of cell types grown are vast.

4. • Generally the cells are sensitive to a wide range of compounds and it is
therefore necessary to ensure that they come into contact only with those
under study and not with extraneous materials.
• Adherent mammalian cells require a suitable surface for attachment.
 Primary cell culture :
• In primary cell culture the cell is first isolated from tissue and then proliferated
under the appropriate conditions until they consume all available contents for
their growth. Now the cell is ready for subculturing by transferring them to new
growth medium that furnish more opportunity for continued growth.
 Type of cell culture :
1. Continuous cell culture
• A continuous cell culture is one that is apparently capable of an unlimited
number of population doublings, often referred to as an immortal cell culture.
2. Finite cell culture
• A finite cell culture is capable of only a limited number of population doublings
after which the culture ceases proliferation.

5.  Stages of cell culture :
Isolated
tissue
Disaggregation
Primary cell culture
Finite cell cultures
Continuous cell lines

6.  Cell line :
• A cell line is a permanently established cell culture that will proliferate indefinitely
in appropriate fresh medium and space.
• In January, 1912, Carrel and his coworkers developed the first “cell line”
derived from the fragments of explanted chicken embryo heart.
• This cell line was subcultured hundreds of times, and after the initial
contamination outbreak, it was continued by Arthur Ebeling in Carrel's
laboratory.
 History of cell line :

7.  To use any cell line for the production of biological product, one should have
knowledge of following things related to cell lines:
• Age, sex and species of the donor tissue.
• For human cell lines, the donor’s medical history and if available, the results of
tests performed on the donor for the detection of adventitious agents.
• Culture history of the cell line including methods used for the isolation of the
tissues from which the line was derived, passage history, media used and history
of passage in animals, etc.
• Previous identity testing and the results of all available adventitious agents
testing.
 Features of cell lines :

8.  Characteristics of cell lines :
 Each cell line is distinguished by characteristic features which render
these cells unique and biomedically or biotechnologically useful.
• The growth pattern and morphological appearance of the cell line
should be determined and should be stable from the master cell bank to
the end-of-production cells.
• If there are specific markers that may be useful in characterizing the cell
line (such as marker chromosomes, specific surface markers), these
should be characterized for stability.
• Mostly cultured cell lines are allowed to generate their own ECM
(extra cellular matrix), but primary culture and propagation of some
specialized cells, exogenous provision of ECM.

9. • Many transformed cell lines have provided the best model for the induction
of differentiation.
• Since normal cells has limited dividing capacity, therefore after a fixed
number of population doublings cell lines derived from normal tissue will die
out. This is a genetically determined event involving several different genes and
this phenomenon is known as senescence. If the cells have an identified finite
life expectancy, the total number of population doubling levels through
senescence should be determined.
• Some cell lines may avoid senescence and give rise to continuous cell lines.
The ability of a cell line to grow continuously probably reflects its capacity for
genetic variation, allowing subsequent selection.
• A common feature of many human continuous cell lines is the development
of a subtetraploid chromosome number. The alteration in a culture that gives
rise to a continuous cell line is commonly called in vitro transformation and
may occur spontaneously or be chemically or virally induced.

10. For the maintenance of Cell line some basic conditions are required. These are
described as follows.
1. pH: Most cell lines grow well at pH 7.4. Although the optimum pH for cell
growth varies relatively little among different cell strains, some normal
fibroblast lines perform best at pH 7.4 to pH 7.7, and transformed cells may do
better at pH 7.0 to pH 7.4.
2. Buffering: Culture media must be buffered under two sets of conditions:
a) Open dishes, where the evolution of CO2 causes the pH to rise
b) Overproduction of CO2 and lactic acid in transformed cell lines at high cell
concentrations, when the pH will fall.
3. Temperature: The temperature recommended for most human and warm-
blooded animal cell lines is 37°C, closely to body heat, but generally set a little
lower for safety, because overheating may become major problem than under
heating.
 Requirements of cell lines :

11. 4. Media: Although many cell lines are still propagated in medium supplemented
with serum, in many instances cultures may now be propagated in serum-free
media. Media that have been produced commercially will have been tested for
their capability of sustaining the growth of one or more cell lines.
5. Growth curve: A growth curve gives three parameters of measurement:
(1) the lag phase before cell proliferation is initiated after subculture, indicating
whether the cells are having to adapt to different conditions;
(2) the doubling time in the middle of the exponential growth phase, indicating the
growth promoting capacity of the medium; and
(3) the maximum cell concentration attainable indicating whether there are
limiting concentrations of certain nutrients. In cell lines whose growth is not
sensitive to density (e.g., continuous cell lines), the terminal cell density indicates
the total yield possible and usually reflects the total amino acid or glucose
concentration.

12. Fibroblast
Types of cell
line
Cell lines Morphology Origin Species Age Ploidy Characteristics
IMR-90
MRC-5 Fibroblast
Fibroblast Lung Human Embryonic Diploid
Lung Human Embryonic Diploid
Susceptible to human
viral infection contact
inhibited
Finite from
normal
tissue
Continuous
from
normal
tissue
HaCaT Epithelial Keratino
cytes
Human Adult Diploid Comification
BRL3A Epithelial Liver Rat New born Produce IGF-2
-
Continuous
from
neuroplastic
tissue
HeLa Epithelial Cervix Human Adult Aneuploid G6PD Type A
B16 Fibroblast Melanoma Mouse Adult Aneuploid Melanin
 Types of cell lines :

13.  Commonly used cell lines :
 Several cell lines are widely used in contemporary research
across various fields. Some of the popularly used cell lines :
1. HeLa Cells : Derived from cervical cancer cells, HeLa cells
are one of the most famous and commonly used cell lines in
biomedical research. They have been instrumental in various
areas, including cancer research and virology.
2. HEK 293 Cells : These are human embryonic kidney cells
that are widely used for the production of recombinant
proteins and the study of gene expression and protein
function.
3. A549 Cells : Derived from human lung adenocarcinoma,
A549 cells are used in lung cancer research, drug testing,
and studies related to respiratory diseases.
HeLa Cells
HEK 293 Cells
A549 Cells

14. 4. MCF-7 Cells : These are breast cancer cells used for breast cancer
research and studies on hormone receptor-positive breast cancer.
5. SH-SY5Y Cells : Derived from human neuroblastoma, these cells are
used in neuroscience research and drug discovery related to
neurodegenerative diseases.
6. U-87 MG Cells : A glioblastoma cell line often used in brain cancer
research and studies on central nervous system disorders.
MCF-7 Cells SH-SY5Y Cells U-87 MG Cells

15.  Uses of cell lines :
• Cell lines are in vitro model systems that are widely used in different fields
of medical research, especially basic cancer research and drug discovery.
• Their usefulness is primarily linked to their ability to provide an indefinite
source of biological material for experimental purposes.
• Being used in vaccine production, testing drug metabolism and cytotoxicity,
antibody production, study of gene function, generation of artificial tissues
(e.g., artificial skin) and synthesis of biological compounds e.g., therapeutic
proteins.

16.  Applications of cell lines :
1. Biomedical Research :
• Cell lines are fundamental tools for studying basic cellular processes such
as cell division, differentiation, and apoptosis.
• They serve as models for understanding disease mechanisms, especially
genetic disorders.
2. Drug Screening and Development :
• Cell lines are used in high-throughput screening to test the efficacy and
toxicity of potential drugs, accelerating drug discovery.
3. Vaccine Development :
• Viral cell lines are employed to produce viral proteins used in vaccine
development, like the influenza vaccine.
4. Cancer Research :
• Cancer cell lines help researchers investigate the molecular basis of
cancer, screen for potential anticancer compounds, and study drug

17. 5. Toxicology Testing :
• Cell lines are used to assess the toxicity of chemicals, drugs, and
environmental agents, reducing reliance on animal models.
6. Gene Expression Studies :
• Researchers study gene regulation, expression patterns, and the effects
of genetic mutations using cell lines.
7. Bioproduction :
• Some cell lines, such as Chinese hamster ovary (CHO) cells, are used in
biotechnology to produce biopharmaceuticals like monoclonal antibodies
and insulin.

18.  Limitations of cell lines :
1. Genetic Stability :
• Cell lines can accumulate genetic changes over time, leading to differences from
the original tissue.
• This instability can affect experimental reproducibility.
2. Lack of Tissue Complexity :
• Cell lines lack the three-dimensional structure, cell-cell interactions, and
physiological conditions found in intact tissues and organisms.
3. Contamination :
• Cross-contamination or misidentification of cell lines can result in unreliable data.
Authentication is crucial to ensure the cell line's identity.
4. Limited Lifespan :
• Most cell lines have a finite lifespan and eventually enter a state of senescence,
limiting their use for long-term studies.

19. 5. Phenotypic Changes :
• Cell lines can exhibit different characteristics from the original tissue due to
adaptation to in vitro conditions.
• This can lead to discrepancies between cell line behavior and in vivo
biology.
6. Ethical Concerns :
• Human cell lines, especially those derived from questionable sources, raise
ethical concerns regarding informed consent, privacy, and usage.
7. Relevance to In Vivo Conditions :
• Findings from cell line studies may not always translate directly to in vivo
situations, necessitating animal or clinical studies.
 In conclusion, cell lines are valuable tools in scientific research, but
researchers must be aware of their limitations. Careful experimental design,
regular authentication, and complementing cell line studies with in vivo
research are essential for maximizing the reliability and relevance of the
findings obtained from cell lines.

20.  Questions :
 7 marks :
1. Describe cell lines in detail ?
2. Give the applications and limitations of cell lines.

21.  1 marks :
1. Define : Cell Culture
• Cell culture is the multifaceted process through which cells are
isolated from animal or plant and their subsequent growth under
controlled artificial conditions, generally outside their natural
environment.
2. Give any two features of cell lines.
• For human cell lines, the donor’s medical history and if available, the results
of tests performed on the donor for the detection of adventitious agents.
• Culture history of the cell line including methods used for the isolation of the
tissues from which the line was derived, passage history, media used and
history of passage in animals, etc.

22. 3. Which are the main three types of cell lines ?
i. Finite from normal tissue
ii. Continuous from normal tissue
iii. Continuous from neuroplastic tisuue
4. Give any three name of the commonly used cell lines.
i. HeLa
ii. HEK 293
iii. MCF-7
5 .Describe in short : Uses of cell lines.
• Cell lines are being used in vaccine production, testing drug metabolism and
cytotoxicity, antibody production, study of gene function, generation of
artificial tissues (e.g., artificial skin) and synthesis of biological compounds
e.g., therapeutic proteins.

23. MCQs:
1. Which is finite cell line from given options ?
a) HeLa b) MCF-7 c) MRC-5 d) HEK 293
2. Comification is characteristics of which cell line ?
a) IMR-90 b) HaCat c) B16 d) MRC-5
3. Who is the develop cell lines for first time ?
a) Arthur Ebeling b) Herbert Boyer c) Robert Hooke d) Carrel
4. Which cells are use in Vaccine production ?
a) Cancer cells b) Chinese hamster ovary c) Viral cells d) U-87 MG Cells
5. BRL3A cell lines are found in which species ?
a) Mouse b) Rat c) Human d) Pig

24.  References :
 https://www.mlsu.ac.in/econtents/315_Unit%203-%20Nomenclature%20and%20Maintenance.pdf
 https://www.researchgate.net/publication/333042040_CELL_LINE_A_REVIEW
 https://www.slideshare.net/Vijayanarasimha1/cell-lines

25. Thank you