Culturing cells has become integral to Biotechnology with
Cell culture techniques
1. Tissue of interest is carefully dissected to expose cells
of the same type
2. Proteolytic (protein digesting) enzymes are added to
digest the intercellular connective tissue to release
3. Then placed in a medium with necessary sugars, salts
and hormones or growth factors.
Antibiotics are sometimes added to prevent bacterial
The culture is then kept in a flask at 370C where
they will grow for up to 30-40 generation –
These cells have been use for hundreds of years
to grow yeast for beer, wine and bread
production as well as making yoghurt
Advantages to this technique
There are several advantages of such culturing techniques:
The speed of propagation is not dependent on the full
reproductive cycle of the organism.
Scientists and plant breeders can be much more selective
about which plants or animals they are going to propagate.
Plants and animal tissue can be grown under sterile
conditions which avoids the need for quarantine and
They can assist in the propagation of endangered species
where natural reproduction was not rapid enough.
Cells can be kept in a liquid nutrient medium in a cold
Cloning a eukaryotic gene in a bacterium for purposes
of protein production e.g. insulin and growth hormone
Cloning whole organisms e.g. Dolly
Cloning stem cells to replace specialized cells e.g.
Culturing skin cells after serious burns
Testing pharmaceutical products to avoid ethical issues
associated with testing on animals
Chemical interference with cell
Drugs alter the physiological state of an organism.
These include antibiotics which can kill
pathogenic organisms, but also can lead to
Social drugs such as nicotine and alcohol can have
deleterious effects on cell function
High concentrations of alcohol can upset cellular
metabolism leading to cirrhosis of the liver
Illegal drugs such as marijuana, heroin,
cocaine, amphetamines, ecstasy all
interfere with cellular activity –
particularly at nerve cells.
The over prescription or inappropriate
use of other drugs (to control pain,
blood pressure and cholesterol) can
lead to addiction and other mental or
When fuels such as coal, gas and
petroleum burn they produce carbon
dioxide, carbon monoxide which adversely
affect cell metabolism. This can lead to
hyperventilation and other respiratory
The accumulation of toxic gases such as
carbon dioxide and carbon monoxide can
cause irreversible damage to haemoglobin
and other enzymes involved with cellular
Highly soluble in water they can be carried
by our underground water supplies to rivers
and seas leading to algal growths or
Arsenic and cyanide are metabolic poisons
which act as inhibitors blocking or
competing for active sites.
Insecticides (DDT) can be detrimental if
overused. They accumulate in soils and
Destroy the ozone layer and in turn
allows more UV light to reach living
organisms. This increase in exposure
can lead to an increase in cell
mutations and skin cancer as well as
damage to microscopic plankton in
oceans, lakes and rivers.