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Food Virology
Food Micro Lab Final Exam
Question | Answer |
---|---|
Define virus. | An obligate intracellular parasite. |
T or F: Viruses can only replicate with a host cell. | True |
T or F: Viruses have their own metabolic capacity. | False |
The genome of a virus is surrounded by a ____ protein layer. | capsid |
Name thee human enteric viruses. | Norovirus, Hepatitis A, Astrovirus, Rotavirus |
T or F: Viruses prefer alkaline pH. | True |
Name two ways which viruses are concentrated. | Ultrafiltration, 10%PEG6000 + 0.3 M NaCl precipitation |
How are viruses analyzed? | Plaque assay or harvest RNA for qRT-PCR |
What are three methods for human norovirus detection? | Electron microscopy, RT-PCR, enzyme immunoassay |
T or F: Electron microscopy can distinguish between strains of viruses. | False |
____ is the method of choice for detecting low virus titers. | RT-PCR |
T or F: RT-PCR can distinguish between virus genogroups. | True |
What are four desirable characteristics for norovirus detection methods? | Sensitive and specific, rapid results, can be used for detection and genotyping, works on a variety of sample types, can distinguish between infectious and non-infectious |
The ISO/CEN method can quantify what viruses? | Hepatitis A and norovirus |
T or F: There is no standardized methods for the diagnosis of enteric viruses. | True |
Name two traditional ligands for human norovirus recognition. | Monoclonal antibodies, polyclonal sera |
Name three novel ligands for human norovirus recognition. | Single chain monoclonal antibodies, peptide antigens, nucleic acid aptamers, HBGA |
Single chain antibodies are often concentrated and purified to use in ____. | EIA |
Quantification of viruses is done using ____. | RT-PCR |
Low levels of viruses can lead to variation of up to __ log. | 1 |
T or F: Viruses in foods are evening distributed. | False |
T or F: There is no regulatory microbiological data available for viruses. | True |
Infectivity assays reduced ____ and increases _____. | inhibitors, sensitivity |
T or F: Infectivity assays can be used to grow norovirus. | False |
Laboratory growth of viruses requires ____ cells. | host |