Laboratory Techniques for Infection Identification Part 1

can physically remove anything present in the solution that is larger than the virions and viruses can be collected in the filtrate:

filters

when an entire organism is used to culture viruses:

in vivo growth

when a single type of tissue or cell (e.g., epithelial cells) are used to for culture:

in vitro growth

culturing using animal cells, flat horizontal cell culture flasks are a commonly used vessel:

in vitro growth

need a solid surface to attach to so they can grow:

anchorage-dependence

can be grown in the presence of a dense layer of bacteria (bacterial lawn) grown in a 0.7% soft agar in a petri dish:

bacteriophages

where the bacterial cells have been destroyed by lytic phages:

plaques

freshly prepared from animal organs or tissues:

primary cell culture

primary cultures usually have a limited life span, because once the cells become too densely packed, they stop growing due to:

contact inhibition

to prevent contact inhibition, cells from a primary cell culture may be transferred to another vessel with fresh growth medium:

secondary cell culture

finite cell lines:

primary cell culture

can be sub-cultured many times or grown indefinitely:

continuous cell line

if the cell lines can grow indefinitely, they are called:

immortalized cell line

may not exhibit anchorage dependency (they will grow in suspension) and may have lost their contact inhibition:

continuous cell line

slows the growth of primary culture cells once they become too dense and begin touching each other:

contact inhibition

immortal cell line which was originally cultivated from tumor cells that were obtained without consent from Henrietta Lacks (patient who died of cervical cancer in 1951):

HeLa cell

first continuous tissue culture cell line and were used to establish tissue culture as an important technology for research in cell biology, virology, and medicine:

HeLa cell

distinct observable cell abnormalities due to viral infection:

cytopathic effects

may include loss of adherence to the surface of the container, changes in cell shape from flat to round, shrinkage of nucleus, vacuoles in cytoplasm, fusion of cytoplasmic membranes and formation of multinucleated syncytia, inclusion bodies in nucleus or cytoplasm, and complete cell lysis:

cytopathic effects

looks for signs of infection in patient’s serum:

serological assay

looks for clumping of a reagent to indicate the presence of a molecule in a sample:

agglutination assay

employs specificity of antigen/antibody interactions to determine if a molecule of interest is present:

agglutination assay

can be used to probe for either an antibody or an antigen in a patient’s serum:

agglutination assay

if probing for an antibody, the latex beads are coated with the antigen corresponding to the antibody of interest. true or false?

true

if probing for an antigen, the latex beads are coated with the antibody corresponding to the antigen of interest. true or false?

true

strains of the same species of pathogen:

serovars

can probe for the unique antigens on the surfaces of different serovars of organism:

agglutination assay

the term ____ comes from the use of patient serum to distinguish between different strains of pathogen:

serovars

can be used to detect a specific virus present in serum:

hemagglutination inhibition assay

many viruses have ____ that causes RBCs to clump (hemagglutination):

surface proteins

surface proteins that cause RBCs to clump (hemagglutinate):

hemagglutinins

highly specific to viral species so we can use them as antigen for serological assays:

hemagglutinins

developed to specifically bind to the hemagglutinins of different viruses:

antibodies

when ____ binds to hemagglutinins, the hemagglutinins cannot cause RBCs to clump:

antibodies

in the absence of antibodies, ____ occurs when RBCs are added to a patient’s serum:

hemagglutination

can be used to determine titer (concentration) of antiviral antibodies in a patient’s serum:

hemagglutination inhibition assay

patient serum is serially diluted (1:2 dilutions), mixed with a standardized amount of virus and incubated:

hemagglutination inhibition assay

highest dilution that blocks agglutination:

titer

used to detect unique nucleic acid sequences of viruses in patient samples:

nucleic acid amplification test

detects the presence of viral DNA in a patient’s tissue or body fluid sample:

polymerase chain reaction

makes many copies of viral DNA segment of interest using short nucleotide sequences called:

primers

binds to specific sequences of viral DNA, enabling identification of the virus:

primers

detects the presence of RNA viruses:

reverse transcriptase PCR

enzyme reverse transcriptase is used to make cDNA from viral RNA in the specimen and the cDNA can be amplified by PCR:

reverse transcriptase PCR

both PCR and reverse transcriptase PCR are used to detect and confirm the presence of the viral nucleic acid in patient specimens. true or false?

true

can neutralize viral infections by coating the virions, blocking the binding:

antiviral antibodies

modified version of the plaque assay (plaque reduction assay):

neutralization assay

we can quantify antiviral antibodies developed during a viral infection in a patient’s serum using:

neutralization assay

enzyme immunoassays (EIAs) = enzyme linked immunosorbent assays (ELISAs). true or false?

true

exploit the specific interactions between antibodies and antigens:

EIA

the enzyme acts as a tag on the detecting antibody and the enzyme catalyzes a reaction that causes a colorless substrate to produce a colored product in ____.

EIA

for viral antigens and require patient sample to be applied to a membrane filter:

EIA

in ____ a primary antibody is used to capture an antigen (e.g., pathogen-specific antigen):

sandwich ELISA

used to quantify antigen-specific antibodies in patient serum for disease diagnosis:

indirect ELISA

microbes can be identified by measuring their unique ____ profiles:

lipid

can vary in chain length, presence or absence of double bonds, and number of double bonds, hydroxyl groups, branches, and rings:

fatty acids of lipids

microbes can be identified by analyzing the ____ present in their membranes by fatty acid methyl ester (FAME) analysis:

fatty acids

extracted from the membranes of microorganisms, chemically altered to form volatile methyl esters, and analyzed by gas chromatography:

fatty acids

____ analysis in bacterial identification results in a chromatogram unique
to each bacterium:

fatty acid methyl ester

each peak in the gas chromatogram corresponds to a particular fatty acid methyl ester and its height is proportional to the amount present in the cell:

fatty acid methyl ester