1. Cell and Tissue Culture
Essential if experimental work on cells is to be done e.g., manipulation of genes, gene analysis, cancer studies, new plant cells.
Stem cells can differentiate
Cell cultures involving animal, plant, bacterial and fungal cells.

2. Growth curve for cells

3. Basic requirements

4. Micro-organisms

5. Batch culture
Grown until maximum strength reached
No dilution
Exponential growth but slows as waste products
build up
Continuous culture
Add fresh media
Remove equal volume of culture
Dilution of culture occurs
Growth phase is maintained

6. Mammalian cell culture
Animal cells:
fragile (need more carefully controlled conditions)
basic requirements similar
growth medium –
balanced salt solution, amino acids, vitamins
glucose, pH indicator/buffer, antibiotics
Essential addition of Animal serum
(foetal bovine serum FBS %)

7. Sequence of events when cells are cultured in vitro
Adhesion
Spreading
Division
Confluence

9. Obtaining cells
Treat tissue with proteolytic enzymes (e.g. trypsin)
Seperate cells to give primary culture
Cells die after a number of divisions secondary culturing is necessary
Longest cell lines come from TUMOURS or transformed cells which have been immortalised NEOPLASTIC and these will cause cancer if put in animals.
Scholar examples in table.

10. Cell growth
Mono-layers grown in plastic flasks
Surface area covered (confluent) cells stop proliferating need to be sub-cultured.
Advantages
mutant cell lines help understanding of cell growth
cell lines can be fused to give new HYBRID cells
cloning and selection experimental work

11. Plant Tissue culture
Similar to animals in many instances but requirements simpler and media easier to prepare.
Under correct conditions plants can regenerate completely as many possess NUCLEAR TOTIPOTENCY.
(Animals too complex to regenerate whole organism)
Regeneration important for ornamental commercial use and to produce pathogen free plants.

12. Method of culture
Explants (small pieces - sterilised)
grown in media (hormones e.g. auxins/cytokinin)
callus produced (undifferentiated mass of cells)
subculture (alter balance of growth regulators to produce shoot/root)
regeneration of whole plants

15. Hybrid Plants
Hybrid plants containing genetic information from 2 species can be produced by PROTOPLAST FUSION.
Remove cell walls (cellulase and pectinase)
fuse protoplasts using electric current
grow to callus (hormones)
stimulate shoot/root growth with hormones
Why?
Overcomes reproductive incompatability
Can produce new variety of plants
Can produce plants with useful characteristics of 2 species.