The Clinical Virology Laboratory Flashcards
Specimen Collection:
- Samples may be collected from the site of _____ _____ or from a site where the virus is being ______ (asymptomatically)
viral pathology
shed
When should specimen be collected after onset of symptoms?
as soon as possible after onset of symptoms
What is the viral transport medium used for?
Used to prevent drying, maintain viability of virus, inhibit growth of contaminants
What specimen are placed in transport medium and what specimens are not?
Are: specimen from contaminated body sites
Are not: specimen from sites that are free from usual flora
Controls pH and keeps sample moist; prevents drying
Hanks Balanced salt solution or buffered broth
stabilizes or “cushions” virus; use fetal bovine serum, albumin, and gelatin
Proteinaceous Supplement
inhibits growth of bacteria and fungi
Antibiotics
signals the pH and indicates if pH is “off”; red/orange color change
pH indicator
collect in a sterile screw-capped container; do NOT use transport medium
spinal fluid
Rub on surface to collect cells and place in transport medium
Swab collection
collect in a sterile container; do NOT use transport medium
Urine collection
collect in anticoagulant such as heparin, EDTA, or sodium citrate; do NOT use transport medium
whole blood collection
If a sample will be processed within 3-5 days use ________ to store and ship on _____ ice.
refrigerator; wet
If sample will be processed after 3-5 days, use ________ at ____‘C or lower. Ship on ______ ice.
freezer; -70’C; dry
If respiratory syncytial virus (RSV) or cytomegalovirus (CMV) is suspected what don’t you do?
DO NOT Freeze
Two general steps in processing most clinical samples for viral culture
centrifugation and addition of antibiotics
following centrifugation of transport medium, the _______ is used to inoculate the cell culture tubes
supernatant
following centrifugation of transport medium, the _______ is used to prepare antigen smears for immunofluorecence testing
sediment
In whole blood samples, the ________ are separted out and used to inoculate cell cultures
leukocytes
In urine samples, _____-_______ urine is used to inoculate cell cultures
well-mixed
cell culture freshly explanted from tissue of origin; may have indigenous contaminants; ex: rhesus monkey kidney
primary cell culture
Cell cultures that have diploid chromosome number; can be passed 50 times so can’t survive long term; ex: MRC-5, MRHF
Diploid (Normal)