• Viral Cultivation Is Used For Quizlet

Skills to develop. Discuss why viruses were originally described as filterable agents.

Describe the cultivation of viruses and specimen collection and handling. Compare in vivo and in vitro techniques used to cultivate virusesAt the beginning of this chapter, we described how porcelain Chamberland filters with pores small enough to allow viruses to pass through were used to discover TMV. Today, porcelain filters have been replaced with membrane filters and other devices used to isolate and identify viruses. Nucleic Acid Amplification TestNucleic acid amplification tests (NAAT) are used in molecular biology to detect unique nucleic acid sequences of viruses in patient samples.

Polymerase chain reaction (PCR) is an NAAT used to detect the presence of viral DNA in a patient’s tissue or body fluid sample. PCR is a technique that amplifies (i.e., synthesizes many copies) of a viral DNA segment of interest. Using PCR, short nucleotide sequences called primers bind to specific sequences of viral DNA, enabling identification of the virus.Reverse transcriptase-PCR (RT-PCR) is an NAAT used to detect the presence of RNA viruses. RT-PCR differs from PCR in that the enzyme reverse transcriptase (RT) is used to make a cDNA from the small amount of viral RNA in the specimen. The cDNA can then be amplified by PCR. Both PCR and RT-PCR are used to detect and confirm the presence of the viral nucleic acid in patient specimens.

HPV SCAREMichelle, a 21-year-old nursing student, came to the university clinic worried that she might have been exposed to a sexually transmitted disease (STD). Her sexual partner had recently developed several bumps on the base of his penis. He had put off going to the doctor, but Michelle suspects they are genital warts caused by HPV. She is especially concerned because she knows that HPV not only causes warts but is a prominent cause of cervical cancer. She and her partner always use condoms for contraception, but she is not confident that this precaution will protect her from HPV.Michelle’s physician finds no physical signs of genital warts or any other STDs, but recommends that Michelle get a Pap smear along with an HPV test.

The Pap smear will screen for abnormal cervical cells and the CPEs associated with HPV; the HPV test will test for the presence of the virus. If both tests are negative, Michelle can be more assured that she most likely has not become infected with HPV. However, her doctor suggests it might be wise for Michelle to get vaccinated against HPV to protect herself from possible future exposure. Clinical Focus - PART 3Along with the RT/PCR analysis, David’s saliva was also collected for viral cultivation. In general, no single diagnostic test is sufficient for antemortem diagnosis, since the results will depend on the sensitivity of the assay, the quantity of virions present at the time of testing, and the timing of the assay, since release of virions in the saliva can vary.

As it turns out, the result was negative for viral cultivation from the saliva. This is not surprising to David’s doctor, because one negative result is not an absolute indication of the absence of infection. It may be that the number of virions in the saliva is low at the time of sampling. It is not unusual to repeat the test at intervals to enhance the chance of detecting higher virus loads. Summary. Viral cultivation requires the presence of some form of host cell (whole organism, embryo, or cell culture). Viruses can be isolated from samples by filtration.

Viral filtrate is a rich source of released virions. Bacteriophages are detected by presence of clear plaques on bacterial lawn.

Animal and plant viruses are detected by cytopathic effects, molecular techniques (PCR, RT-PCR), enzyme immunoassays, and serological assays (hemagglutination assay, hemagglutination inhibition assay). The LibreTexts libraries are and are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Unless otherwise noted, LibreTexts content is licensed. Have questions or comments? For more information contact us at or check out our status page at.

Viral Cultivation Is Used For Quizlet

Cultivation of Viruses.1.Cultivation of VirusesMICROBIOLOGYIslam Ghassan Sarakbi: 39.A virus is a biological agent that reproduces insidethe cells of living hosts.When infected by a virus, a host cell is forced toproduce many thousands of identical copies of theoriginal virus, at an extraordinary rate. Unlike mostliving things, viruses do not have cells that divide;new viruses are assembled in the infected hostcell.Viruses can't be grown in culture media oron agar plates alone, they must have livingcells to support their replication.The easiest viruses to grow arebacteriophages (because the easiest cellsto grow in the lab are bacteria).On the other hand, Viruses can be cultivatedwithin suitable hosts, such as a living cell. Tostudy bacteriophages, for example, bacteria aregrown in a suitable growth medium, thenbacteriophages are added.The bacteriophages multiply within the bacteriaand increase their numbers substantially.Purpose Of Virus Cultivation The primary purposes of viral cultivation are:1.To isolate and identify viruses in clinical specimens.2. To prepare viruses for vaccines.3. To do detailed research on viral structure,multiplication cycles, genetics and effects on host cells.Virus Cultivation Systems Tissue culture system. Embryonated eggs system. Whole animal systems.Tissue culture system For CultivationOf VirusesAnimal and plant viruses are cultivated in cellcultures. A cell culture is prepared byencouraging cell growth outside the animal orplant source.

The cells are kept alive in asuspension of growth factors within a Petridish. A thin layer of cells, or monolayer, isthen inoculated with viruses, and replicationtakes place.Tissue culture system For Cultivation OfViruses(Fertilized eggs and living animals can also beused to cultivate viruses.)For research study, viruses can be cultivatedin large volumes by inoculations to tissueculture systems.