Page 108 - MNU-PM503 Parasitology practical book

Pharm D- Clinical Pharmacy Program Third Level Parasitology and virology (PM501)

in the appropriate state for the virus(es) being sought, that is, confluent or

actively dividing; at the appropriate temperature, that is, 37° or 33° (for

respiratory viruses); and that the laboratory periodically checks the cell lines

being used for their continuing sensitivity to support growth of reference

viruses.

4. Evidence that a new virus has been isolated may come from routine reading of

monolayers for cytopathic effects (CPEs), which may be distinctive for a

particular virus. Alternatively, monolayers may be screened by a variety of

techniques including antigen staining, hemadsorption, electron microscopy, or

PCR. Blind passage of material not showing a CPE may be advisable to identify

slow-growing agents, and regular comparison with uninoculated control cells

is essential to distinguish viral CPE from degeneration of uninfected cell

monolayers.

5. Finally, a variety of methods may be needed to obtain final identification of the

virus that has been isolated, sometimes including detailed strain identification or

sequencing.

Cell Cultures

• Cell Cultures are most widely used for virus isolation

• There are 3 types of cell cultures:

1. Primary cells - Monkey Kidney

2. Semi-continuous cells - Human embryonic kidney and skin fibroblasts

3. Continuous cells - HeLa, Vero, Hep2, LLC-MK2, MDCK

95