Flashcards in Cell and Tissue Culture Deck (37):
What is cell and tissue culture?
The growth of cells tissues or organs in artificial media in a laboratory.
What can culturing produce?
Genetically identical clones of an initial cell sample.
What ways can cells be grown?
In suspension using a liquid medium
Or within a solid medium (substrate) such as agar jelly.
How are anaerobic organisms cultured?
In non-aerated suspension or within agar.
What can be done to prevent inoculation with cells and spores?
Use of sterile materials.
Treatment of source tissue
What is the effect of contamination?
Bacteria or fungal contamination will rapidly outcompete and spoil culture of slower growing plant or animal cells.
What can strains be cultured in?
Suspension and fermenters
What does nutrient agar contain?
Agar with peptides and beef extract added
What does malt agar contain?
Agar with malt extract added
Why are plates incubated at temperatures other than body temperature?
To reduce the chance of culturing harmful pathogens
In mammalian cell culture what is contained in the complex growth factor?
Growth factors, and antibiotics.
What can growth factors be provided by?
The addition of an animal serum, such as foetal bovine serum.
What is foetal bovine serum?
It is a mixture containing growth factors, proteins, salts, vitamins and glucose.
What is the purpose of adding antibiotics
To minimise the chances of spoilage by microorganisms
How are cells or culture detached from the source tissue.
Using proteolytic enzymes such as trypsin.
What happens after the mammalian cells are added to the flask?
They adhere to the surface of the agar
Flatten or spread out
Start to divide
What is the name given to a layer one cell thick?
When do the cells stop dividing?
When the cells are confluent, they have completely covered the surface.
How do you keep a cloned cell line alive?
Some of the cells must be subcultured into a new flask as the nutrients in the medium get used up.
How are the cells removed from the monolayer?
Using proteolytic enzymes.
What is the Hayflick limit?
The maximum number of times a cell can divide before dying
What does the Hayflick limit result in?
Reduces the length of time a culture can be maintained
Where can you find immortal cell lines?
From those derived from cancer cells or stem cells, which can be subcultured indefinitely.
Why are stem cells desirable for tissue culture?
They are pluripotent or even totipotent
Why are Murishige and Skoog slats used in a plant growth medium?
They contain an appropriate balance of macronutrients, micronutrients, carbon sources and vitamins
What can also be added to stimulated differentiation in plant cells?
Growth regulators such as cytokinins and auxins.
What can plant cells be described as?
What do the two main methods of plant tissue culture use?
Explants or protoplasts
What are explants?
Small pieces of plant tissue that are placed on a solid medium to either promote shoot growth or callus growth..
What is organ formation stimulated by?
Altering the ratio of cytokinins (to promote shoot growth) and auxins (to promote root growth).
What enzymes are used to digest cell walls creating protoplasts?
Pectinase and cellulase
How are the protoplasts grown?
In a liquid medium as a cell suspension culture.
They treated with growth regulators to induce embryogenesis to generate whole new embryonic plants.
What can protoplasts be encouraged to form?
What do cell suspension cultures allow?
Screening for beneficial traits or selection of virus free cells for cloning.
Used to harvest useful plant cell secretions
Can you give examples of beneficial traits.
Heat or salinity tolerance.
What is micropropagation?
The generation of many cloned plantlets from one source plant.