This document discusses different types of mammalian cell culture. It describes primary cell culture, which uses cells directly from tissue that can undergo a limited number of divisions before senescing. Finite and continuous cell lines can proliferate for extended periods through transformation or immortalization. Common cell lines include HeLa cells and other tumor-derived lines. The document also covers techniques for attachment and suspension cell culture, and factors that influence cell growth in vitro.

1. ASSIGNMENT
ANIMAL TISSUE CULTURE
TOPIC:-MAMMALIAN CELL
SUBMITED TO:- SUBMITED BY:-
CANDY MAM MOIN KHAN HUSSAIN

2. Mammalian Cell Culture
Cell culture of mammalian cells.
Eukaryotic cells are much more difficult to culture than most prokaryotes.
They demand complex media
They are very susceptible to contamination and overgrowth by microbes such as bacteria, yeasts and
fungi.
Cell Culture
Two types of cell culture
Primary Culture
Cell Line Culture
• AKA – finite / continuous / established / secondary / subclone / immortalized cell culture
Primary Culture
Come from the outgrowth of migrating cells from a piece of tissue or from tissue that is disaggregated
by enzymatic,
chemical, or mechanical methods.
Formed from cells that survive the disaggregation process, attach to the cell culture vessel (or survive
in
suspension), and proliferate.
Primary cells are morphologically similar to the parent tissue.
These cultures are capable of only a limited number of cell divisions, after which they enter a
nonproliferative state
called senescence and eventually die out.
Primary cells are considered by many researchers to be more physiologically similar to in vivo cells.
Primary cell culture is generally more difficult than culture of continuous cell lines.
Advantages
They are thought to represent the best experimental models for in vivo situations.
Have the same karyotype as the parent tissue normal or abnormal.
Not “dedifferentiated”
Disadvantages
Difficult to obtain.
Relatively short life span in culture.
Very susceptible to contamination
May not fully act like tissue due to complexity of media
Considerable variation in population and between preparations
Tumor Primary Cell Culture
Easier to create as tumors cell cycle / growth regulators have been altered
Tumor cells often produce own growth factors (autocrine)
Mechanically disrupted tissue easily plates, binds and can thrive
Finite Cell Lines
AKA – secondary or subclone culture
Finite cell cultures are formed after the first subculturing (passaging) of a primary cell culture.
These cultures will proliferate for a limited number of cell divisions, after which they will senesce.
The factors which control the replication of such cells in vitro are related to the degree of differentiation
of the cell
The cells will proliferate for an extended time, but usually the culture will eventually cease dividing,
similar to

3. senescent primary cells.
Use of such cells is sometimes easier than use of primary cell cultures, especially for generation of stably
transfected clones.
Advantages
Can obtain a large population of similar cells.
Most cellular characteristics are maintained
Can transform cells to grow indefinatly
Disadvantages
Cells have a tendency to differentiate over time in culture.
Over time the culture tends to select for aberrant cell
Continuous Cell Line
A cell line that has demonstrated the potential to be subcultured indefinitely.
Infinite cell line
Immortal cells line
Immortalized cell lines are also known as transformed cells:
Cells whose growth properties have been altered.
Finite cell cultures will eventually either die out or acquire a stable, heritable mutation that gives rise to
a continuous
cell line that is capable of unlimited proliferative potential.
This alteration is commonly known as in vitro transformation or immortalization and frequently
correlates with
tumorigenicity.
Continuous cell lines are generally easier to work with than primary or finite cell cultures.
These cells have undergone genetic alterations and their behavior in vitro may not represent the in
vivo situation.
HeLa Cells
Classic example of an immortalized cell line.
These are human epithelial cells from a fatal cervical carcinoma transformed by human papillomavirus
18
(HPV18).
Advantages
Easy to maintain in culture.
Easy to obtain large population of cells.
Typically easy to manipulate gene expression.
Disadvantages
The more aggressive the cell line the more it changes over time in culture.
Not clear how the function of these cells relates to that of other cells, healthy or diseased.
Transformed Cells
Transformed, Infinite or Established Cells
Changed from normal cells to cells with many of the properties of cancer cells.
Some of these cell lines have actually been derived from tumors or are transformed spontaneously in
culture
by mutations.
Chemical or gamma ray treated cells can become infinite with loss of growth factors
Viral infection with SV40 T antigen can insert oncogenes and lead to p58 and RB gene alteration
No matter how transformation occurred, the result is a cell with altered functional, morphological, and
growth characteristics.

4. Characterization by Cell Growth
Attachment Cultures
To survive and grow, most cells require a surface to which they can attach
Without the surface attachment these cells cannot survive
The advantages of adherent growth is the ability of the cells to adhere and spread on surfaces such as
coverslips,
making microscopy, hydribidizations, and functional assays more easily performed.
Suspension Cultures
Some cells can survive and divide while being suspended in a fluid media and stirred or
shaken.
• Flasks
• Spinner Cultures
• Shaker Cultures
A limited number of cell types can be
maintained and grown in either format.
The advantages of suspension growth are the large numbers of cells that can
be achieved, and the ease of harvesting.
Growing Cells in Culture
Place cells in a culture dish.
Give them nutrients, growth factors, keep them free from bacterial.
Cells will grow to cover the surface of the dish.
Can take cells out of this culture and start a new culture.
Splitting cells from one dish to another is a passage.
Number of Cell Divisions
This ability to split cells and have them continue to divide is not without limits
however.
Normal cells have a limit to the number of times which they can be passed in
culture.