The viral DNA synthesis experiment determines when viral DNA synthesis begins. Infect cells, add 3H-thymidine. Remove aliquots every 2 minutes, hybridize to filters containing cold phage DNA. Determine when rise in viral DNA occurs. Handed DNA encoding ORF3 of Phage 1065. How would you determine whther the .8kb mRNA for ORF3 is amplified after viral [...]

Viruses have three major differences from bacteria: their genome organization, characteristic mode of replication, and effect on host cell (either death, fusion, or transformation). Viruses are not alive in and of themselves. Instead, they are obligate intracellular parasites capable of replication and reproducing within living cells. A complete virus particle or virion may be regarded [...]

As with bacterial colonies, it is easy to screen for presence of a virus. When overlaid onto a bacterial lawn, a single virion will create a visible clearing in the lawn. These clearings are called viral plaques, and the virion responsible is called a plaque forming unit (pfu). A large percentage of virions produced will [...]

Pathogenesis is disease. Normal flora are part of host’s normal microbial community. Primary pathogens infect healthy hosts. Opportunistic pathogens infect compromised hosts. Virulence is a quantifiable measure of pathogenicity. Parasites do not kill the host. Parasite: consume host resources at host expense. A parasite is an organism that lives in or on the living tissue [...]