2. TYPES OF CELL CULTURES:
Cell culture is classified into three:
Primary cell culture
• Adherent cell culture
• Suspension cell culture
Secondary cell culture
Cell line
• Finite cell line
• Continuous cell line
2
3. Primary culture
3
It is the stage of culture after isolation of cells but
before the first subculture after which it becomes
cell line
Four stages
Acquisition of the sample
Isolation of tissue
Dissection/ disaggregation
culture
4. 4
Fat and necrotic tissues are best removed during
dissection.
Tissue should be chopped finely to cause
minimum damage.
Enzymes used for disaggregation should be
removed subsequently by gentle centrifugation.
5. PRIMARY CELL CULTURE:
Separate cell directly from the parent tissue (
kidney, liver, heart etc.)
Separated by enzymatic or mechanical method.
Maintaining the growth of the cell in a culture
medium using glass or plastic container.
Culture medium
Liquid or gel designed to maintain the growth of the
cell.
It varies from different type of cell.
5
6. Primary cell culture is further classified based on the
types of the cells.
Adherent cell :
Cells shown to require attachment for growth are
said to be anchorage dependent cells.
The adherent cells are usually derived from tissues
of organs such as kidney where they are immobile
and embedded in connective tissue.
Those cell which attach to the surface of the culture
flask.
Forms a monolayer.
They have to be detached from the surface before
they get sub cultured.
Growth limited to surface area.6
7. Suspension cell
Cells which do not require attachment for growth
or do not attach to the surface of the culture
vessels are anchorage independent
cells/suspension cells.
All suspension cultures are derived from cells of
the blood system because these cells are also
suspended in plasma in vitro i.e. They are free
floating.,Cells in blood stream. e.g. lymphocytes.
Growth is limited to concentration of cells.
7
8. SECONDARY CELL CULTURE:
When a primary culture is sub-cultured, it
becomes known as secondary culture or cell line.
Subculture (or passage) refers to the transfer of
cells from one culture vessel to another culture
vessel.
This is periodically required to provide fresh
nutrients and growing space for continuously
growing cell lines.
The process involves removing the growth media
and disassociating the adhered cells (usually
enzymatically).
Such cultures may be called secondary cultures.8
9. CELL LINE:
A cell line or cell strain may be finite or continuous
depending upon whether it has limited culture life
span or it is immortal in culture.
On the basis of the life span of culture, the cell
lines are categorized into two types:
Finite cell lines -
The cell lines which have a limited life span and go
through a limited number of cell generations
(usually 20-80 population doublings) are known as
finite cell lines.
These cell lines exhibit the property of contact
inhibition, density limitation and anchorage
dependence. The growth rate is slow and doubling9
10. CONTINUOUS CELL LINES:
Cell lines transformed under laboratory conditions
or in vitro culture conditions give rise to
continuous cell lines.
These cell lines show the property
of ploidy (aneupliody or heteroploidy), absence
of contact inhibition (cells growing into a single
layer) and anchorage dependence.
They grow either in a monolayer or in suspension
(see below). The growth rate is rapid
and doubling time can be 12-24 hours.
10
11. Monolayer cultures -
When the bottom of the culture vessel is covered
with a continuous layer of cells, usually one cell in
thickness, they are referred to as monolayer
cultures.
Suspension cultures -
Majority of continuous cell lines grow as
monolayers.
Some of the cells which are non-adhesive e.g.
cells of leukemia or certain cells which can be
mechanically kept in suspension, can be
propagated in suspension.11