Viral Culture Flashcards
What is the viral culture?
It’s the growth and propagation of viruses in a laboratory setting.
List the reason’s for viral culture
1) Antiviral drug production.
2) Vaccine production
3) Understanding the evolution of virus over time i.e knowing the mutated and variants.
4) Understanding Viral behaviours, properties and interactions with host cell.
Give an example of virus that needs BLOOD as a specimen
HIV
Hepatitis B and C virus.
Dengue fever
Example of virus that needs urine as specimen
Zika virus
Examples of virus that uses Saliva/sputum as specimen
Viruses that spread via respiratory droplets e.g
RSV, Influenza
Examples of viruses that uses stool as a specimen
G.I.T viruses; Rotavirus and norovirus
Example of viruses with swabs as samples include:
Surface body lesion virus e.g HSV and varicella zoster
List the methods of Viral cultivation
Animal innoculation.
Embryonated cell inoculation.
Tissue inoculation
Explain Animal inoculation
It’s the primary method of isolation of viruses.
Here viruses are inoculated into animals.
Especially in Suckly rats of less than 48hrs old.
This method is used to study the pathogenesis and clinical manifestation of a virus.
It also aids diagnosis.
List the examples of viruses inoculated in animals
Toga virus.
Coxsackie virus
Explain embryonated egg innoculation
Embryonated eggs are cultured for 7-12 days.
Preferred location of nick with respect to the virus is marked.
It’s cleaned with antiseptic to avoid bacteria infxn.
Virus is introduced into the nick and opening is closed with paraffin wax.
It’s incubated at 36°c for 2-3days allowing the virus to replicate and grow.
What are POCKS
They’re greyish white lesion seen on the chorioallantoic membrane of an embryonated egg.
What does one POCKs signify
It indicates the clinical manifestation of pox virus on embryonated egg.
Give me example of Virus innoculated in the chorioallantoic membrane
Pox virus
HSV virus.
Rous sarcoma virus.
Give me example of Virus innoculated in the yolk sac
HSV
Give me example of Virus innoculated in the Amniotic cavity
Influenza and Mumps
Give me example of Virus innoculated in the allantois cavity
R- Rabies virus
Y- yellow fever
I- influenza
M- mumps
List the three types of tissue culture technique
Tissue/organ culture.
Explant
Cell lines
Describe organ culture mechanism.
This is used in the study of viral replication, growth and it’s pathogenesis.
It provides a physiological relevant environment for the viral study.
Organs are tissue part of interested are isolated and cut into pieces
Then it is placed into a nutrient rich medium where it’s allowed to grow and multiply.
What are the examples of organs or tissue that can be used for organ culture
Lung tissue
Liver tissue
Skin tissue
Tracheal ring.
What is the disadvantage of the organ tissue culture.
It requires maximum technical know how.
It requires detailed attention in:
a) Maintaining the viability of the organ/tissue
b) Preventing the risk of contamination
Tracheal ring tissue culture is used to culture which viruses
Respiratory viruses;Tracheal ring
HSV
Hepatitis
What is the advantage of explant culture over organ culture
It involves the study of replication and pathogenesis of virus in a more physiological relevant condition.
Here virus interacts with cells and tissues
Are explant culture specimen and virus examples same with that of ORGAN/TISSUE culture?
Yes or No
Yes.
What is explant culture;
It is a technique in which living cells or tissues are removed from an embryo for continued development outside of the organism
Which of the cell culture technique is routinely used in the laboratory
Cell line culture
What are the uses of cell line culture
Virus isolation,
Virus identification,
Viral growth,
Vaccine production
How is cell line culture obtained
Tissue is obtained and grown in a nutrient rich medium.
It’s then trypsinized to form cluster of cells..
This clusters are washed then placed in a tube or petriplate in suitable conditions necessary for growth.
On incubation cell line replicate or grow to form a monoconfluent layer that is extracted.
Virus is introduced into this monoconfluent layer
The rich nutrient media of cell line culture is made up of?
Balanced salt concentration.
Essential amino acids.
Glucose
Lipids
Antibiotics,
Buffering agent,
Serum.
Methylene red/ phenol
On what basis is cell line divided into it’s three groups?
Origin of cell.
Chromosomal characteristics.
Number of generations through which cell culture can be maintained.
List the types of cell line;
Primary,
Semicontinuous (diploid)
Continuous cell line.
Which type of cell line is a normal ce obtained fresh from animal or human organ?
Primary cell line
List the features of a primary cell line:
They cannot be maintained in a serial sub culture.
Origin: it’s gotten fresh from animal and human organs.
They are used for isolation of virus and preparation of vaccines
Example of a primary cell line includes;
Monkey Kidney cell line, human amnion cell line
What are the features of semi continuous cell line
Site of origin; Embryonic tissue
They are fibroblastic.
Diploid cell– Chromosomal characteristics .
Can be subcultured for limited generation about 50 serial sub groups.
There’s rapid cell division, with 50 serial sub culture.
After which they undergo senescence and die off.
Diploid cells are susceptible for a wide range of human virus culture.
T or F
True
Examples of semicontinuous cell line includes;
Rhesus embryonic cell.
Human embryonic lung strain e.t
.c
Which cell line is capable of growth invitro
Continuous cell line
What are the features of Continuous cell line
Origin: cancerous cells
Infinite growth.doesnt reach senescence.
Chromosomal characteristics: Haploid
Can be serially subcultured infinitely
Examples of continuous cell line
Hela cells ; gotten from cancerous growth of the cervix.
Hep-2 ;. Human epithelioma of larynx strain… type 2
Vero kindey(velvet monkey)
Continuous cell line can be maintained with serial sub culture or by freezing @70°c T or F
Truth
Continuous cell line is used for isolation and not for vaccination T or F?
True
Why are virus of continuous cell line not used to produce vaccines?
This is because vaccines produced through this mechanism aren’t safe.
