CHAPTER 6 - AGGLUTINATION Flashcards
(114 cards)
1
Q
Process by which particulate antigens (agglutinogen) such as cell aggregate to form larger complexes when a specific antibody (agglutinin) is present
A
AGGLUTINATION
2
Q
particulate antigens
A
agglutinogen
3
Q
specific antibody
A
agglutinin
4
Q
published the first report about the ability of antibody to clump cells, based on observations of agglutination of bacterial cells by serum
A
Gruber and Durham
5
Q
2 STAGES OF AGGLUTINATION
A
6
Q
Antigen-Antibody reaction
A
SENSITIZATION
7
Q
Cross linking
A
LATTICE FORMATION
8
Q
Visible agglutination
A
LATTICE FORMATION
9
Q
No agglutination yet
A
SENSITIZATION
10
Q
Forms bridges between Ab and Ag
A
LATTICE FORMATION
11
Q
Represents binding of Ag and Ab
A
SENSITIZATION
12
Q
Stabilization of antigen–antibody complexes with the binding together of multiple antigenic determinants.
A
SENSITIZATION
13
Q
FACTORS THAT AFFECT AGGLUTINATION
A
14
Q
Routine Buffer pH
A
pH 7
15
Q
(physiological pH)
A
7.35 – 7.45
16
Q
Affects the zoning phenomenon
A
Relative concentration of Ag and Ab
17
Q
Abs will not detect determinants buried within the particle
A
Location and concentration of Antigenic determinants of the particle
18
Q
More number of determinants, the higher the likelihood of cross bridging
A
Location and concentration of Antigenic determinants of the particle
19
Q
Electrostatic interactions between particles
A
Non covalent interaction
20
Q
(Zeta potential)
A
Electrolyte concentration
21
Q
in the buffer plays an important role in agglutination
A
Electrolyte concentration (ionic strength)
22
Q
: charge bet RBC and the elctrolyte/ECF
A
Zeta potential
23
Q
Zeta potential:
in RBC
outside the body
A
↑
↓
24
Q
reduce electrostatic charges that interfere with lattice formation
A
Electrolytes
25
Antibody isotope Best: l
IgM
26
(dealing w/ particulate Ag)
IgM
27
IgM: Cold reacting with optimum temperature at
4-22oC
28
IgG: Warm reacting with optimum temperature at
37oC
29
Incubation times ranges from
15-60 minutes
30
No agglutinates
0
31
Dark, turbid, homogenous
0
32
Many tiny agglutinates, many free cells, may not be visible without microscope
W+
33
Dark, turbid
W+
34
Many small agglutinates, many free cells
1+
35
(25% are agglutinated)
1+
36
Turbid
1+
37
Many medium sized agglutinins, moderate number of free cells
2+
38
(50% are agglutinated)
2+
39
Clear
2+
3+
4+
40
Several large agglutinates, few free cells
3+
41
(75% are agglutinated)
3+
42
One large solid agglutination, no free
4+
43
(100% are agglutinated)
4+
44
MAJOR CATEGORIES OF AGGLUTINATION REACTIONS
45
Reaction is due to an Ag-Ab reaction where in the Ag is inherent (inside) native to the cell
Direct Immune
46
Direct Immune Example:
ABO grouping (hemagglutination), Widal Test
47
Aggregation of indicator rod blood cells are NOT due to Ag-Ab reaction
Direct Non Immune
48
Direct Non Immune Example:
Viral Hemagglutination test
49
Virus can stick to agglutinate RBC in the process
VIRAL HEMAGGLUTINATION
50
VIRAL HEMAGGLUTINATION viruses
Rubella virus, dengue virus, influenza virus, mumps virus
51
Viral receptor: (binds RBC)
Peplomers
52
Competitive binding Assay
VIRAL HEMAGGLUTINATION INHIBITION (HAI)
53
Procedure:
1. Patient serum w/ Ab incubated with viral particles (Commercially available)
2. Viral particles will bind to the Fab region of Anti-viral Abs
3. Indicator RBCs added to reaction mixture
VIRAL HEMAGGLUTINATION INHIBITION (HAI)
54
VIRAL HEMAGGLUTINATION INHIBITION (HAI)
Positive result:
Negative result:
Inhibition or Absence of Agglutination (Presence of Ab)
Agglutination
55
Reactions where Ag has been fixed or absorbed to a carrier/ inert particle
INDIRECT/ PASSIVE AGGLUTINATION
56
INDIRECT/ PASSIVE AGGLUTINATION Example:
Antistreptolysin-O (ASTO)
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Different passive carriers:
Human RBCs
Clay (Bentonite)
Latex particles
Colloidal gold
Charcoal particles
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Antibody is bound to the carrier
REVERSE PASSIVE AGGLUTINATION
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Fluid is detected for the presence of Ag
REVERSE PASSIVE AGGLUTINATION
60
REVERSE PASSIVE AGGLUTINATION Example:
CRP, Reverse agglutination test for Candida and Nisseria
61
Patient sample (Ag) incubated with Ab in test kit
LATEX PARTICLE AGGLUTINATION INHIBITION
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Complex will form if the patient sample contains the corresponding Ag and the Fab sites are no longer available for the Ag-coated latex particles
LATEX PARTICLE AGGLUTINATION INHIBITION
63
LATEX PARTICLE AGGLUTINATION INHIBITION Example:
HCG/ pregnancy test, Screening test for Drug
64
Systems using bacteria as the inert particles to which antibody is attached
COAGULATION
65
- most frequently used bacteria in COAGULATION
Staphylococcus aureus
66
– responsible for attaching Ab to the bacteria; naturally adsorbs the fragment crystallizable (FC) portion of antibody molecules
Protein A
67
The active sites face outward and are capable of reacting with specific antigen
COAGULATION
68
Detects IgG Ab bound to Ag on Red cells (in-vivo) Purpose:
Direct Antiglobulin Test
69
Direct Antiglobulin Test Purpose:
Hemolytic Disease of the Newborn investigation
Hemolytic Transfusion Reaction investigation
Autoimmune Hemolytic Anemia
70
Direct Antiglobulin Test Example:
Direct Coomb’s test
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– maternal Ab attacking the fetal RBC
Hemolytic Disease of the Newborn investigation
72
– recipient Ab attacking the donor RBC
Hemolytic Transfusion Reaction investigation
73
– selfAb attacking own RBC
AIHA (Autoimmune Hemolytic Anemia)
74
Detects presence of Abs in the serum that is still to be attached to an analyte (invitro)
ANTIGLOBULIN TEST
75
ANTIGLOBULIN TEST Purpose:
Crossmatching
Ab determination
Ab identification
RBC Ag phenotyping
76
ANTIGLOBULIN TEST Example:
Indirect Coomb’s test
77
– metabolite of drug attached to RBC
Drug induced Hemolytic Anemia
78
In concentration or in exact value
QUANTITATIVE AGGLUTINATION REACTION
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SPIA/ Sol Particle Immunoassay
Gold-inorganic colloidal particle
80
DIA/ Disperse Dye Immunoassay
Dye-organic colloidal particle
81
IMPACT/ Immunoassay by Particle Counting
Latex particle
82
Best QUANTITATIVE AGGLUTINATION REACTION
IMPACT/ Immunoassay by Particle Counting
83
VIRAL HEMAGGLUTINAT ION INHIBITION (HAI)
Reagent/s:
Unknown:
1) Viral particles 2) Indicator RBC
Antibody
84
INDIRECT/ PASSIVE AGGLUTINATION
Reagent/s:
Unknown:
Antigen
Antibody
85
REVERSE PASSIVE AGGLUTINATION
Reagent/s:
Unknown:
Antibody
Antigen
86
LATEX PARTICLE AGGLUTINATION INHIBITION
Reagent/s:
Unknown:
1) Antibody 2) Ag-coated latex particle
Antigen
87
VIRAL HEMAGGLUTINAT ION INHIBITION (HAI)
(+) Result
88
INDIRECT/ PASSIVE AGGLUTINATION
(+) Result
89
LATEX PARTICLE AGGLUTINATION INHIBITION
(+) Result
90
COAGULATION
Unknown
(+) Result
Ag
Agglutination
91
This finding gave rise to the use of serology as a tool in the diagnosis of disease, and it also led to the discovery of the ABO blood groups (Karl Landsteiner)
AGGLUTINATION
92
Antigen and antibody unite through antigenic determinant sites.
Sensitization
93
Sensitization or Lattice formation
Particulate Ags: w/ multiple determinants
Sensitization
94
Sensitization or Lattice formation
Cross-linking or bridging
Lattice formation
95
Rearrangement of antigen and antibody bonds to form stable lattice.
Lattice formation
96
Blood type determines the Ag present in RBC
ABO grouping (hemagglutination)
97
Ex.
A = AAg
B = Bag
AB = AB Ag
O = None (w/o A or B Ag)
ABO grouping (hemagglutination)
98
ABO grouping (hemagglutination) Types:
1. Forward Typing
2. Reverse Typing
99
– employs use of antisera containing Abs
Forward Typing
100
Types of anti-sera:
Anti-A and Anti-B
101
Competition between the Viral particle (VP) and Indicator RBC (I. RBC) for the binding sites of the Ab
102
[Px serum w/ Ab + Viral particle w/ Ag = Ag-Ab binding] + [Indicator RBC (to indicate agglutination)]
(+) Result:
No Agglutination
103
[Px serum w/o Ab + Viral particle w/ Ag = Ag-Ab binding] + [Indicator RBC (to indicate agglutination)]
VP binds w/ I. RBC due to peplomer to show agglutination
Result:
Agglutination
104
Antigen is attached to the carrier particle, and agglutination occurs if patient antibody is present.
INDIRECT/ PASSIVE AGGLUTINATION
105
Antibody is attached to the carrier particle, and agglutination occurs if patient antigen is present.
REVERSE PASSIVE AGGLUTINATION
106
REVERSE PASSIVE AGGLUTINATION
Has a fab site facing outwards, which is important to detach Ag
Ab
107
REVERSE PASSIVE AGGLUTINATION
– portion of Ab attached to the coated particle
Fc portion of the Ab
108
Reagent antibody is added to the patient sample.
LATEX PARTICLE AGGLUTINATION INHIBITION
109
If patient antigen is present, antigen–antibody combination results.
LATEX PARTICLE AGGLUTINATION INHIBITION
110
When antigen-coated latex particles are added, no agglutination occurs, which is a positive test.
LATEX PARTICLE AGGLUTINATION INHIBITION
111
If no patient antigen is there, the reagent antibody combines with latex particles, and agglutination results, which is a negative test.
LATEX PARTICLE AGGLUTINATION INHIBITION
112
Screening test for Drug
THC -
MET -
CONTROL – for
THC - marijuana
MET - methamphetamine (shabu)
CONTROL – for the validity of the test
113
Screening test for Drug Result
1 line for CONTROL -
1 line for MET –
positive for both
positive for THC
114
Same as reverse passive agglutination but bacteria is used instead of carrier particles to w/c Ab is attached
COAGULATION
