Cultivation of Viruses

Question 1

is it easier to grow bacteria or viruses

Answer 1

bacteria

Question 2

ways to grow/cultivate viruses

Answer 2

cell/tissue culture
inoculation in embryonated eggs
laboratory animals

Question 3

organ culture

Answer 3

parts of an organ or a whole organ are cultured in-vitro

Question 4

cell culture

Answer 4

growth of cells in artificial media outside host

Question 5

suspension culture

Answer 5

cells which do not require attachment for growth or do not attach to the surface of the culture vessels

Question 6

monolayer culture

Answer 6

bottom of the culture vessel is covered with a continuous layer of cells, usually one cell thick.

Question 7

primary cell culture

Answer 7

growth of cells dissociated directly from the parental tissue of animal/human origin. cells share the same chromosomes as the original tissue. Heterogeneous. short life span. closest to animal cells, used in producing viral vaccines

Question 8

secondary cell culture & two types

Answer 8

when a primary culture is sub-cultured (transferred to another culture vessel). Grow quickly. Two types- finite and continuous

Question 9

finite/diploid cell lines

Answer 9

limited life span and a limited number of cell generations. can sub-culture up to 100x before cells die. Growth is slow (doubling time 24-96hrs)

Question 10

continuous/immortal/heteroploid cell lines

Answer 10

divide indefinitively. immortal cells lines. subcultures after subcultures and still maintained. Growth is rapid (doubling time is 12-24hrs). Cannot use for vaccination.

Question 11

fibroblastic morphology

Answer 11

cells are bipolar or multipolar, have elongated shapes, and growth attached to a substrate

Question 12

epithelial-like morphology

Answer 12

cells are polygonal in shape with more regular dimensions, and growth attached to a substrate in discrete patches. clumps

Question 13

lymphoblast-like morphology

Answer 13

cells are spherical in shape and usually grown in suspension without attaching to a surface. detached living in suspension

Question 14

cell culture media

Answer 14

provides all the necessary nutrients (AAs, inorganic salts, vitamins, and glucose) required for the growth of cells

Question 15

serum in culture media

Answer 15

vital source of adhesion factors, attachment and spreading factors. Most used- fetal bovine serum (FBS)

Question 16

phenol red

Answer 16

pH indicator, detects contamination via a pH change. metabolic waste can also lead to change in pH. Changes color when pH decreases (acidity)

Question 17

antimicrobial agents in media

Answer 17

to prevent contamination wit bacteria, mycoplasma, yeast, molds, etc.

Question 18

human and mammals optimal cell line growth temperature

Answer 18

36-37ºC

Question 19

insect optimal cell line growth temperature

Answer 19

27ºC

Question 20

avian optimal cell line growth temperature

Answer 20

38.5ºC

Question 21

cold-blooded animals optimal cell line growth temperature

Answer 21

15-26ºC

Question 22

shell vial technique

Answer 22

inoculate with specimen, centrifuge to enhance infection monolayer, incubate at 35ºC for 1-5d, stain with anti-viral fluorescent monoclonal antibodies, mount coverslip on slide, read with fluorescent microscope

Question 23

cultivation of viruses in eggs

Answer 23

specific pathogen free eggs, egg candler, betadine, sterile swab, drill, microdrill bits

Question 24

infertile egg

Answer 24

cannot be used in viral growth

Question 25

fertile egg

Answer 25

can be used in viral growth

Question 26

yolk sac inoculation

Answer 26

place inoculum below the embryo and within the yolk material

Question 27

allantoic cavity inoculation

Answer 27

inoculate specimen into the allantoic cavity

Question 28

amniotic cavity inoculation

Answer 28

into amniotic cavity

Question 29

chorioallantoic membrane inoculation (CAM)

Answer 29

drill 2 holes, move air sac to the side of the egg, inoculate on the dropped CAM

Question 30

evidence of virus growth inside egg

Answer 30

embryo death, paralysis, stunted growth, urate deposits in the mesonephros, hemorrhage, hemagglutins in embryonic fluids, extracellular membrane lesions

Question 31

pocks

Answer 31

necrotic lesions due to viral replication

Question 32

pocks assay determines…

Answer 32

number of pocks determine viral infection

Question 33

ultracentrifugation

Answer 33

gravitational force of 200,000 x 150.000 RPM. efficiently sediment even the smallest viruses

Question 34

rate-zonal centrifugation

Answer 34

sample is layered. density gradient. bands are formed depending of substances masses. light particles settle slow, heavy particles settle quick

Question 35

isopychic centrifugation/buoyant or equillibrium separation

Answer 35

particles will never sediment to the bottom of the tube, state with a uniform mixture. use cesium chloride as a suitable density gradient medium

Question 36

buoyant density

Answer 36

if the object has exactly the same density as the fluid, then its buoyancy equals its weight. it will remain submerged in the fluid, but it will neither sink nor float

Question 37

isopycnic point

Answer 37

the point where the buoyant density of a particle equals that of the surrounding density gradient medium

Question 38

Binding of the viruses on ion exchange membranes depends on……….

Answer 38

the charge distribution on the virus