Cultivation Of Viruses Flashcards
Describe why there is no growth in plate inoculation of viruses.
-viruses dont have the genetic capability to multiply by division
-outside the host cell they are inert/dormant particles
-viruses need living host cell to replicate & gen next progeny of viruses
-inside the host cell the virus hijacks & utilizes the host cell machinery to make its proteins & nucleic acid for the next gen of virus
Describe the possible ways to grow/cultivate viruses.
- Cell/tissue culture
- Inoculation in embryonated egg
- Lab animals
Describe suspension cultures VS monolayer cultures.
- Suspension = cells dont require attachment for growth or dont attach to the surface of the culture vessels (can be propagated in suspension)
- Monolayer = bottom of culture vessel is covered w continuous layer of cells (one cell thick)
Describe primary cell cultures & its ADV & DISADV.
maintenance of growth of cells dissociated from parental tissue of human/animal
ADV:
-best culture system for isolation & propagation of viruses
-heterogenous (many cell types)
-closest to animal tissue cells
-used in producing viral vaccines
DISAV:
-difficult to obtain
-short lifespan in culture
-sus to contamination
-may not fully act like parent tissue bc complexity of culture media
Describe subculture/passage/secondary/transfer culture.
-transfer of cells from one culture vessel to another
-periodically required to provide fresh nutrients & growing space for cont growing cell lines
Describe the two types of cell lines.
- Finite/diploid cell lines
-cell lines have a limited life span & go thru limited # of cell gen - Continuous cell line
-acquire ability to divide indefinitely
Describe finite cell lines.
-homogenous pop of single cell type - fewer cell types
-limited life span
-derived from embryos or secondary cell cultures
-cell retained original morphology & diploid chromosome #
-contact inhibition, density limitation, & anchorage dependence
-slow growth rate & doubling time (24-96h)
-less hassle
-used in vaccine production
Describe continuous/immortal/heteroploid cell lines.
-cell cultures of single cell type = most homogenous
-derived directly from cancer cells
-abnormal morphology & chromosome #
-absence of contact inhibition & anchorage dependence
-growth rate is rapid & doubling time is 12-24h
-hassle free
-cannot be used for vaccine production
EX: Henrietta Lacks -> HeLa cells
Describe the 3 morphology of cells in culture.
- Fibroelastic =
-spindle shaped
-bipolar or multi
-elongated shape
-grow attached to substrate - Epithelial like =
-polygonal
-rectangular dimensions
-grow attached to substrate in patches - Lymphoblast like =
-spherical
-grown in suspension without attaching to a surface
Describe culture medium.
-provides all necessary nutrients (AA, inorganic salts, vit, glu) required for growth of cells
Describe serum in culture media.
-fetal bovine serum (FBS) mostly used
-required for growth & maintenance of cells
-help w cell adhesion
-regulate cell membrane permeability
-provide nutrients
Describe phenol red pH indicator.
Indicated change in pH (fall in pH) by changing color of medium from red to orange
Describe CO2 level.
Necessary to use exogenous CO2 when using media buffered w CO2 bicarb based buffer to maintain pH of media
Describe antimicrobial agents.
-prevent contamination w bacteria, mycoplasma, yeast, mold, etc
Describe proteases.
-trypsin = proteolytic enzyme used to detach & dissociate cells while subculturing
