Test 2 Quiz Questions Flashcards
A radial immunodiffusion test is run for 72 hours. The concentration of the antigen is then calculated using the:
Square of the diameter of the precipitation ring 
If an Ouchterlony immunidiffusion pattern shows in ark equidistant between antigens A and B, this indicates that the antigens: 
Are identical
In a capture assay to determine the presence of a viral antigen in a patient sample, which of the following would be on a solid phase? 
Unlabeled antibody
Compared to a heterogeneous assay, a homogeneous assay: 
Is easier to adapt to automation
Fluorescently labeld antibodies are used in flow cytometry to determine: 
Proteins associated with a cell
An intrinsic parameter that can be measured by a flow cytometer is:
Granularity
Which test can be used in confirming the Specificity of serological screening assays ?
Western blots 
The best method to determine deposition of IgG complexes on the basement membrane of kidney is using
Immunofluorescent staining
A patient’s wbc’s are placed in culture. H – Thymidine is added to the cultures 48 hours later, and the amount of radioactivity incorporated in DNA (CPM) will be measured.  What would be added to simulate Proliferation of both T & B cells?
PWM
The production of insoluble complexes that absorb or scatter light but are too small to see directly is called:
Precipitation
A good enzyme for use in an immunoassay should have a: 
High substrate conversion rate
A child in day care has developed pneumonia. A child in a nearby daycare also has a respiratory infection, but not as severe. Samples from each child is found to have influenza virus using PC. Restriction enzyme digests of the amplified samples shows identical banding patterns. What conclusion can be drawn from these results?
The child may have been exposed to a common source of the cause of their illness
When a patient’s red blood cells combine with antigen A-typing serum to produce a positive result, the reaction is known as: 
Hemagglutination 
How would you interpret results of DNA restriction analysis by gel electrophoresis if there was a difference in one band?
The samples are not identical
What process confirms specificity in molecular biology methods? 
Hybridization
In flow cytometry, it is possible to detect the expression of 10 different cell membrane proteins stimulated by:
Staining the cells with 10 different labeled probes that fluoresce different wavelengths
And flow cytometry, if there are two light detectors, what does the amount of side scatter indicate?
Granularity of the cell
18. Which of the following best describes homogenous assays?
a.
The reagent antibody has an enzyme tag
b.
The concentration of patient antigen is always directly proportional to the label detected
C.
A washing step is not necessary
d.
Labeled and unlabeled analyte are present in equal amounts
C . A washing step is not necessary
A serological reaction is set up in which the antigen is bound to a large carrier, the antibody is soluble and the antigen and carrier bind and form an insoluble complex that is detected macroscopically. What type of assay is described?
Agglutination
If A serum sample causes a slight or marginal agglutination reaction when mixed with a particulate antigen then you should: 
Test a more diluted sample
Pregnancy testing can be performed at home using: 
Immunochromatography
In most flow cytometer‘s, labeled cells: 
Scatter the light and emits florescence
An intrinsic parameter that can be measured by light scatter in a flow cytometer is: 
Cell size 
A fluorescent signal and flow cytometry is generated by: 
Fluorochromes that absorb energy from a laser beam and then release the energy as a longer wavelengths 
If anybody is uniformly distributed in a gel and antigen is added to a well cut into the gel, process is called:
 radial diffusion
reverse passive agglutination test?
Antibody is attached to particles
Nitroblue tetraoleum is added to patients wbc’s. Under microscopic examination, neutrophils but not lymphocytes are deep blue color. What is likely true?
Phagocytes are able to produce reactive oxygen species
In polymerase chain reaction, the first cycle showing a positive signal: 
And indication of the original amount of target in the sample
A tissue section is fixed to a microscope slide, then incubated with a fluorescently labeled antibody that binds to an antigen expressed by cells in that tissue. The precipitation is then washed and inspected with a fluorescent microscope. This technique is called: 
Direct immunofluorescence
A serological test that uses red blood cells coding with exogenous antigens such as bacterial polysaccharides as a method to detect patient antibodies against those exogenous antigens is called: 
Hemagglutination
What best describes a factor important for competitive binding assays? 
A limited number of binding sites are present 
Flow cytometry is commonly used for: 
Determine the stage of leukocyte differentiation
As measured in flow cytometry, cells that are the smallest and have the least granules would be identified as:
Lymphocytes
if an Ouchterlony immunodiffusion pattern shows an arc between antigens A and B with an extended line pointing towards antigen B this indicates that the antigens: 
Share a common epitope with A being a more complex antigen
An immunoassay is a performed In the following way: Antigen is bound to a solid support. Patient serum is added, and patient antibodies bind to the antigen. The well is washed and Enzyme labeled anti-immunoglobulins antibodies are added. Enzyme activity is determined. What immunoassay is described? 
ELISA
An ELISA assay was performed on a patient serum sample. What is the relationship of the amount of enzyme activity to the amount of patient analyte measured?
Directly proportional
The measurement of the light scattered at an angle by the antigen-antibody complexes in a solution is called:
Nephelometry
A patient is being treated for HIV Infection. Before treatment, real time PCR results for viral load had a cycle threshold (CT) Of 28, but after two months of treatment a CT of 24 was found these results indicate:
The viral load is increasing
When carrier particles are coated with an antigen that is not normally found on them this is known as:
Passive agglutination
reverse passive agglutination test?
Antibody is attached to particles
In performing blood typing using the tube method, if the red blood cell button is not resuspended properly, what are the most likely results?
False positive
What is characteristic of a passive agglutination test?
Antigen molecules are artificially bound to particles
Fluorescent signal and flow cytometry is generated by:
Fluorochromes that absorb energy from a laser beam and then release the energy as a longer wavelength light
An immunoassay is performed in the following manner to look for antigen (Ag) in the patient serum: Patient serum + labeled Ag + known antibody (Ab) are added together and incubated. Unbound material is washed off. The amount of labeled Ag is then measured. What assay is performed?
Competitive
If crossed lines result in an Ouchterlony immunodiffusion reaction with antigens A and B, this indicates antigens A and B:
Are entirely different
Point-of-care testing is performed most easily using:
Immunochromatographic assay
Compared with a capture assay, a radioimmunoassay is likely to be more advantageous in terms of:
Detecting small molecules
Select the strand of RNA that is complementary to this single strand of DNA: TTAAGCCGTA
a. AAUUCGGCAU
b. AATTCGGCATA
C. UAAUCGGCUAU
d. TUUTCGGCAUA
a. AAUUCGGCAU
What is meant by “gating” in flow cytometry?
An electronic window separating subpopulations of cells
