LEC3 - REVIEW OF BASIC SEROLOGY Flashcards
involves combining soluble antigen with soluble antibody to produce insoluble
complexes that are visible
Precipitation
the most efficient Ig for precipitation
IgG
is the process by which particulate antigens aggregate to form larger complexes when a specific antibody
is present.
Agglutination
most efficient in agglutination
IgM
antigens mainly found on
the surface of a particles. These particles can be
naturally or synthetically attached to a carrier
particle.
particulate antigen
IgG can also perform this but it needs to be
incubated at ____* C to enhance the agglutination
reaction
37
it is the visible aggregation of particles caused by combination with specific antibody
agglutination
Antibodies that produce such agglutination are often
called
____.
agglutinins
Agglutination involves a two-step process:
___ and ___
Sensitization and then Lattice Formation
Types of particles participating in agglutination
include ___
erythrocytes, bacterial cells, and inert carriers
such as latex particles.
Agglutination reactions can be classified into several
distinct categories:
o Direct agglutination
o Passive Agglutination
o Reverse Passive agglutination
o Agglutination Inhibition
o Coagglutination
o AHG-Mediated Agglutination
the most important category among the Agglutination reactions categories is the
AHG mediated agglutination
the initial interaction between antigen and antibody
sensitization
will there be a complex formed in sensitization?
none
is there a stability formed between the antigen and antibody interaction in sensitization stage?
alaws pa po
The first reaction involves antigen–antibody
combination through SINGLE antigenic determinants on
the particle surface
sensitization
a step of agglutination wherein it’s about the Initial binding. No complex formed
sensitization
Sum of interactions between antibody and multiple
antigenic determinants on a particle
Lattice formation or formation of large aggregates
Antibody must be able to bridge the gap between cells
in such a way that one molecule can bind to a site on
each of two different cells.
Lattice formation
Erythrocytes and bacterial cells have a slight negative
surface charge, and because like charges tend to
repel one another, it is difficult to bring such cells
together into lattice formation.
true or false
true
where there is a distance
between RBCs and bacterial cells
Zeta potential
a normal distance of rbc from each other and other cells that keeps them away from each other – repelling
25 nm apart
IgM with a potential valence of 10 is over _______
times more efficient in agglutination than is IgG with a
valence of 2
700
Wingspan of IgG is
15nm
Since IgG is small, it is not
able to connect antigen from different particle. Visible
reactions with IgG often require the use of
enhancement
medium like
22% albumin,
polyethylene glycol,
Low Ionic Strength Solution
(LISS),
incubating at 37C, adding of AHG reagent
commonly used enhancement medium.
Also used in crossmatching
Low Ionic Strength Solution
(LISS)
an enhancement medium for IgG that removes water from the
system. Removing water will lead to a high
concentration of antibodies that will improve
RBC sensitization.
polyethylene glycol
When using PEG, ___after 37C
incubation is not required.
centrifugation
Most sensitive type of enhancement
medium
polyethylene glycol
PEG is not applicable in samples that have
elevated plasma protein (multiple myeloma
pxs) because _______
precipitation of protein will
occur instead of agglutination
TYPES OF AGGLUTINATION REACTION
Direct Agglutination
Passive Agglutination
Reverse Passive Agglutination
Agglutination Inhibition
Coagglutination
AHG-Mediated Agglution
a type of agglutination reaction that occurs when antigens are found naturally on a
particle.
Direct Agglutination
Direct Agglutination
Can be done on ___ or ____
glass slides or test tubes
If an agglutination reaction involves red blood cells, it
is called
Hemagglutination
Hemagglutination is routinely done at ___ without enhancement technique
room
temperature
example of Hemagglutination
ABO blood typing
serological test where we are using known bacterial antigens
widal test
weil felix test
used to test for the
presence of unknown antibodies in the patient’s serum
known bacterial antigen
a rapid screening test to help determine
the possibility of typhoid fever
widal test
antigen used in widal test
Salmonella O (somatic) and H (flagellar)
antigens
bacterial suspension used for weil-felix test
proteus spp as they have the same antigenic determinants
weil-felix test detects what infection
rickettsial infection
the abo testing we are conducting is usually at room temperature, please explain why?
because the antisera that we are using is mainly IgM in nature, which works at room temp or even colder temp
criteria of agglutination under slide method
weak agglutination
strong agglutination