1. Biotechnology – Biotechnological techniques
Use of micro-organisms
Industrial production of enzymes
Tissue cultures

2. Cell cultures are used routinely to
Cell culture is the cultivation of animal and plant cells in the laboratory
Cell cultures are used routinely to
produce materials e.g. vaccines and hormones,
to test the safety of medicines
to study the properties of cells in isolation e.g. insulin production in the pancreas

3. Animal Cell Culture
It is possible to grow cells from different organs e.g. pancreas
Stem cells have also been cultured and are used to grow human cartilage and also brain cells (specialised from stem cells)

4. Pancreas cells in tissue culture
(usually animal cells have to be grown attached to a surface e.g. plastic. They are said to be anchorage dependant. The exception to this are body fluid cells e.g. blood cells)

5. Limitations
Animal cells are fragile and sensitive to damage.
A lack of a cell wall makes them vulnerable to changes in osmotic concentrations within growth media.
Too costly to carry out on a large scale.

6. Procedure
Cells are grown in plastic flasks or dishes.
Air is carefully bubbled into the vessels (no shaking as this would damage cells)
1st batch of cells (primary cell line) are removed from the stock mechanically and with the help of enzymes e.g. proteases
Cell lines grown for many generations

7. Conditions
Similar to those for microbes
Aseptic technique is essential. Often carried out in an aseptic tissue culture cabinet.

9. Growth media – cocktails of nutrients are needed.
Antibiotics are added to prevent the growth of bacterial contaminants.

10. Plant Cell Culture
It is easier to grow plant cell cultures than to collect plants from the environment.
Cell cultures are used to:
Study the biological and physical properties of plant cells isolation.
Grow cells in a fermenter to collect metabolites for making drugs, dyes, fragrances and pharmaceuticals.
Develop improved crop plants.

11. Conditions
The following need to be considered.
Temperature
Nutrient supply
Light intensity
Aseptic technique is essential. Often carried out in an aseptic tissue culture cabinet.

12. Growth of Explants
An explant is any portion of a plant that is used to make a culture e.g. leaf disc
These are then grown on petri dishes with the appropriate nutrients.
Calluses (mass of plant cells) form from the explants
Calluses are transferred into flasks or dishes containing the appropriate media and are grown up into adult plants.

14. Plant cells can also be grown in suspension in fermenters.
An explant is taken and then it must be treated with pectinases to separate the plant cells from each other.
They are then transferred into fermenters and can be subcultured from the fermenter.
For example, Lithospermum plants are used to produce the antibacterial and anti-inflammatory drug: shikonin.

16. Protoplasts Protoplasts are used to:
make monocultures of plants i.e. genetically uniform plants (clones). This is useful for crop plants as the uniformity means that they will all grow/flower/fruit at the same rate.
Make genetically pure plant cell tissue lines.
Engineer genetic hybrids that would be sexually incompatible in nature.

17. Plant tissue or cells from a callus can be used.
Their plant cell walls are removed by enzymes e.g. pectinases and cellulases.
Plants are then regenerated from the plant cell protoplasts.

19. Hybridisation
Protoplasts can be used for hybridisation/protoplast fusion techniques. These fuse the nuclei of 2 genetically separate species.
This can overcome sexual incompatibility between plant species
Introduce genes for herbicide and pest resistance

20. The Technique (aseptic)
Protoplast of species 1 Protoplast of species 2
e.g. potato plant e.g. disease resistant plant
Treated with cellulose and pectinase Treated with cellulose and pectinase
to remove cell wall to remove cell wall
Mix with polyethylene glycol (dehydrates protoplasts)
Protoplasts fuse
Protoplast develops into a callus (treated with auxin and cytokinin for root and shoot growth)
Hybrid plant displays the characterisitics of both parents
disease resistant, edible potato plant
Contains genetic information from both protoplasts (parents)
e.g. disease resistant, edible potato plant

21. 2 different Brassica species
Hybrid plant the result of protoplast fusion

22. Past Paper Questions
2005 Q2 b
2006 Q3

23. Use the resources available to you
Monograph
Scholar
Brock
AH SQA answers
Previous study, knowledge and text books
To address the arrangements documents