Plant and Animal Tissue Culture and Propagation
Plant and Animal Tissue Culture and Propagation tests aseptic establishment, culture media, growth regulators, regeneration, and scale-up of plant and animal cells.
Core rules
- Plant micropropagation starts with an explant, surface sterilization, and culture on a nutrient medium such as MS salts with sucrose, vitamins, and growth regulators.
- Auxin and cytokinin balance morphogenesis. A high auxin-to-cytokinin ratio favors roots; a high cytokinin-to-auxin ratio favors shoots; an intermediate ratio favors callus.
- Somatic embryogenesis produces bipolar embryos; organogenesis produces shoots or roots directly or indirectly.
- Animal cells require sterile media, serum or defined supplements, controlled temperature, and often 5% CO2 for buffering. Primary cells have finite lifespan; continuous lines are immortalized.
- Subculture before confluence, monitor passage number, and test for mycoplasma.
Worked example
Banana shoot tips are surface-sterilized with sodium hypochlorite, rinsed, and placed on MS medium with benzyladenine to multiply shoots. Once shoots are 2-3 cm, they are transferred to medium with indole-3-butyric acid for rooting. Rooted plantlets are acclimatized in a humid chamber before field transfer. The reasoning is that cytokinin drives shoot multiplication, while auxin shifts development toward roots.
Traps
Do not treat hormone concentrations as fixed recipes; genotype and explant age change the response. Do not assume all regenerated plants are clonal; somaclonal variation occurs. Do not add antibiotics routinely to plant cultures. Do not let animal cultures overgrow or ignore mycoplasma, which can pass filters and lacks a cell wall.