Module 4 End of Chapter Questions Flashcards
The quality of test results in an agglutination reaction depends on all of the following except:
Duration of incubation
amount of antigen conjugated to the carrier
avidity of antigen conjugated to the carrier
whether the carrier is artificial or biological
Whether the carrier is artificial or biological
Flocculation procedures differ from latex agglutination procedures because
Soluble antigen reacts with antibody
In the hemagglutination technique, antihuman globulin is used as an enhancement medium to detect ___ antibodies
IgG
The prozone phenomenon can result in a
false-negative reaction
The effect of competing antibodies seeking to attach to antigen sites is called
steric hindrance
the description of a mixed-field graded agglutination reaction is
Few isolated aggregates; supernatant appears red
the description of a 1+ graded agglutination reaction is
A few small aggregates: turbid and reddish supernatant
The description of a 2+ graded agglutination reaction is
Medium-sized aggregate; clear supernatant
The description of a 4+ graded agglutination reaction is
All erythrocytes are combined into one solid aggregate; clear supernatant
the definition of precipitation is
Aggregation of soluble test antigens
the definition of agglutination is
Aggregation of particulate test antigens
the definition of coagulation is
uses antibodies bound to a particle to enhance visibility of agglutination
the definition of flocculation is
Based on the interaction of soluble antigen with antibody, resulting in the formation of a precipitate of fine particles
the definition of hemagglutination is
Agglutination of erythrocytes in tests for antibody detection
artificial or biological carrier that can be used in an agglutination reaction include:
latex particles
colloidal charcoal
erythrocytes coated with antigen in a constant amount
all of the above
all of the above
sensitization:
is the first phase of agglutination
represents the physical attachment of antibody molecules to antigens on the RBC membrane
is an irreversible reaction
both a and b
Both a and b
agglutination can be used to enhance reactions by all of the following means except:
decreasing ionic strength of the reaction
centrifugation
increasing the pH of the reaction
using colloids and antihuman globulin
Increasing pH of the reaction
A negative latex agglutination reaction would appear as
no aggregates
A weak (1+ or 2+) latex agglutination reaction would appear as
tiyn aggregates that are barely visible macroscopically
A 3+ latex agglutination reaction would appear as
several large aggregates
all of the following statements are correct regarding human pregnancy testing except:
test detect hCG
the hCG is secreted by the trophoblast of the developing embryo
the presence of hCG rapidly increases in urine or serum
The presence of hCG in maternal urine or serum persists throughout pregnancy
the presence of hCG in maternal urine or serum persists throughout pregnancy
All of the following statements are correct regarding hCG except:
it helps maintain the corpus lateum
it stimulates production of progesterone
it is detectable within 102 hours after the last expected menstrual period
it reaches peak levels at 2 to 3 months after the last menstrual period
It is detectable within 102 hours after the last expected menstrual period
A urine specimen for pregnancy testing ___ be frozen
may
Nephelometry measures the light scatter of
macromolecules
Nephelometry can be used to assay all of the following except:
IgM
IgG
IgD
IgA
IgD
Protein can be separated into ___ fractions by use of serum electrophoresis
five
immunofixation electrophoresis (IFE) is primarily used in the
detection of monoclonal gammopathy
IFE can test
serum
urine
CSF
The primary use of IFE is
characterization of monoclonal immunoglobulins
IFE can be used to detect the protein variable of
electrophoretic mobility
Most M proteins are
IgG
chemiluminescence:
has excellent sensitivity and dynamic range
does not require sample radiation
The description of competitive immunoassay is
A fixed amount of labeled antigen competes with unlabeled antigen from the patient specimen for a limited number of antibody-binding sites
the description of sandwich immunoassay is
A sample antigen binds to antibody fixed onto solid phase; chemiluminescent-labeled antibody binds to the antigen-antibody complex
enzyme labels often used in indirect procedures are
alkaline phosphate
horseradish peroxidase
beta-galactosidase
the description of the enzyme immunoassay (EIA) is
uses a nonisotopic label
The description of the immunofluorescent technique assay is
uses antibody labeled with fluorescein isothiocyanate (FITC)
the description of the direct immunofluorescent assay is
uses conjugated antibody to detect antigen-antibody reactions
the description of inhibition immunofluorescent assay is
Antigen is first exposed to unlabeled antibody, then to labeled antibody
the description of indirect immunofluorescent assay is
Based on antibodies acting as antigens and reacting with antiimmunoglobulins
for an enzyme to be used in an EIA, it must meet all of the following criteria except:
high amount of stability
extreme specificity
prescence in antigen or antibody
no alteration by inhibitor with the system
Presence in antigen or antibody
A fluorescent substance is one that ___light of one wavelength
Absorbs
A fluorescent substance has the dual characteristic of ___ light of another longer wavelength
Emitting
Which of the following molecules are detected by the enzyme-linked immunoassay (ELISA) technique?
proteins
peptides
hormones
all of the above
All of the above
What is the major advantage of enzyme-linked immunoassay (ELISA) compared with other quantification labeling methods?
Detection of an antigen or antibody at a low concentration
