Cultivation of viruses Flashcards
outside host, viral cells are ???
DORMANT
3 possible ways to grow/cultivate viruses
- cell/tissue culture
- inoculation in embryonated egg
- lab animals
2 types of cell cultures
- suspension culture: cells which do not require attachment for growth or do not attach to the surface of the culture vessel - can be propagated in suspension
- monolayer culture: when the bottom of the culture vessel is covered with a continuous layer of cells, usually one cell in thickness, they are referred to as a monolayer culture
primary cell culture
maintenance of growth of cells dissociated directly from parental tissue of animal or human
primary cell culture:
advantage (4)
disadvantage (4)
+: best system for isolation and propagation of viruses, heterogeneous - many cell types, closest to animal, used in producing viral vaccines
-: difficult to obtain, short lifespan in culture, susceptible in contamination, may not fully act like parent tissue due to complexity of culture media
secondary culture/transfer culture
-required to ?
-need to do to ?
subculture refers to the transfer of cells from one culture vessel to another culture vessel
-required to provide fresh nutrients and growing space for continuously growing cell lines
-do to get more cells!!
2 types of cell lines
- finite/diploid cell lines: cell lines which have a limited life span and go through a limited number of cell generations
- continuous cell lines: acquire the ability to divide indefinitely
Finite cell lines/diploid cell lines = ?
homogenous population of a single cell type - fewer cell types
limited life span and mostly derived from embryos or secondary cell cultures
cell has original morphology and DIPLOID chromosomes
finite cell line properties (3)
growth rate fast or slow?
alot of hassle?
contact inhibition (no overgrowth, 1 line of cells), density limitation and anchorage dependence
growth rate is slow
less hassle to use
which type of cell line can be used for vaccination production?
finite cell lines !!!
continuous cell lines/immortal cell lines = ?
derived directly from?
cell culture of a single cell type - most homologous – derived directly from cancer cells!!
genetically weird - furthest from animal - abnormal morphology and chromosome number
continuous cell lines/immortal cell lines have absence of ?
growth rate?
absence of contact inhibition and anchorage dependence
fast growth rate and hassel free
–cannot be used for vaccine production!!
example of continuous cell line
henrietta lacks – HeLa cells
Morphology of cells in culture (3)
- fibroblastic - spindle shaped and grow attached to a susbstrate
- epithelial like cells - polygonal shape and grow attached to a substrate in patches
- lymphoblast like cells - spherical shape and grow in suspension without attaching to surface
culture medium =
provides all necessary nutrients (AA, inorganic salts, vitamins and glucose) required for growth of cells
