T/F: It is easier to cultivate bacteria than cultivating viruses
T/F: Viruses have the genetic capability to multiply by division
Viruses need a living host cell to replicate and generate next progeny viruses
What are some ways used to grow/cultivate viruses?
Cell tissue culture
inoculation in embryonated egg
What are monolayer cultures?
Cell cultures that use cells grown in-vitro and are dispersed as a single layer on a solid surface (flat)
Compared to a cell suspension in a test tube
What is the best culture system for isolation and propagation of viruses?
Primary cell culture
***used in vaccine production
What is the term for the transfer of cells from one culture vessel to another culture vessel?
why is this done?
Subculture or passage
*this is periodically required to provide fresh nutrients and growing space for continuously growing cell lines
What are two cell lines used to grow viruses?
Finite diploid cell lines: cell lines which have a LIMITED lifespan and go through a LIMITED number of cell generations
Continuous cell lines: acquire the ability to divide indefinitely
Where are finite cell lines derived from?
Mainly from embryos, or from secondary cell cultures
These are more homogenous than primary cell lines - more cells of the same type
*easier to use
T/F: Finite cell lines exhibit contact inhibition
What cell lines are used for vaccine production?
Finite cell lines
What kind of cells are used as continuous cell lines?
Typically cancer cells/oncogenic cells
**These are the MOST homogenous
Do continuous cell lines exhibit contact inhibition?
***this is why they are not used for vaccine production (they are genetically abnormal)
What is used to provide cell lines with nutrients for growth?
Ex: Eagles basal medium
What is the most widely used animal serum supplement for cell growth in culture? What is its function?
FBS - fetal bovine serum
Required for growth and maintenance of cells, helps in cell adhesion, regulates cell membrane permeability, and provides nutrients
What is the purpose of Phenol Red pH indicator?
Indicates change in pH (a decrease) by changing the color of the medium from red to orange
Helps you monitor cell cultures. The pH drop is due to cell excretions over time or fungal contamination
What is the importance of using a carbon dioxide-bicarbonate buffer?
to maintain the pH medium
*virus cultures are kept in a Carbon dioxide incubator
How do you prevent contamination with bacteria, yeasts, molds etc?
Antimicrobial agents within the media
What is trypsin? Why is it important in cell/virus culture?
Proteolytic enzyme used to detach and dissociate cells while subculturing
*loosens up the cells from each other and the plate for transfer
What is the term used to describe the damage or morphological changes to host cells during virus invasion?
Cytopathic effcect or cytopathogenic effect (CPE)
What is the process by which a fertilized egg is inoculated directly into the yolk?
Yolk Sac Inoculation
What is the process by which a fertilized egg is inoculated directly into the allantoic cavity?
Allantoic cavity inoculation
What is the process by which a fertilized egg is inoculated directly into the amniotic cavity?
Amniotic Cavity Inoculation
Virus inoculation can occur in four different compartments within the egg. What are they? (4)
Yolk sac inoculation
Allantoic cavity inoculation
Amniotic Cavity inoculation
Chorioallantoic membrane inoculation (CAM)
What signs will you see that confirm virus growth within an egg?
Death of the embryo
Paralysis or sluggish movement)
T/F: intracerebral inoculation and intraperitoneal inoculation are common methods of laboratory animal inoculation?
How can you check an egg to see if it is embryonated?
What is a characteristic sign seen on the chorioallantoic membrane after virus inoculation
Pocks on the Chorioallantoic membrane