Studied by 9 people
Immunologic Reactions
Reactions involving antigens and antibodies, classified into primary, secondary, and tertiary.
Primary Phase
The stage of immunologic reactions where antigens and antibodies combine, typically non-visible.
Secondary Phase
The stage where visible antigen-antibody reactions occur, such as agglutination or precipitation.
Tertiary Phase
The stage where biological effects such as phagocytosis and opsonization are observable.
Direct
The test that detects a known antigen on the specimen using a known anti-sera.
Indirect
The test that detects unknown antibodies on the patient serum using a known commercial antigen.
Precipitation Test
A test that measures the formation of a visible precipitate in a fluid medium when antigen and antibody react.
Nephelometry
A technique measuring scattered light to determine the concentration of insoluble complexes formed by antigen-antibody reactions.
Turbidimetry
A method that measures the decrease in light intensity in a solution of antigen-antibody complexes.
The _____ the light intensity, the ____ the concentration of complexes.
Lower, Higher
Size of particles
Temperature
Gel viscosity and hydration
Factors that affects Immunodiffusion:
Radial Immunodiffusion (RID)
A single diffusion, double dimension immunodiffusion technique.
Fahey and Mckelvey
The kinetic method of RID.
read after 18 hours.
multiple measurements are also performed.
Mancini
The Endpoint method of RID.
IgG is read at 24-48 hrs.
IgM is read at 50-72 hrs.
Oudin test
The most simple single diffusion, single dimension immunodiffusion technique.
Antigen diffuse towards the agar gel, no electrical current needed.
Result is a Precipitin Line
Ouchterlony test
A double, diffusion, double dimension immunodiffusion technique.
widely used for comparing antigens.
Identity
they will form a smooth arc in an Ouchterlony test.
Partial Identity
A spur- shaped line appears in the ouchterlony test.
Non-Identity
A crossing lines form in the ouchterlony test.
Oakley and Futhrope
A double (linear) diffusion, single dimension Ouchterlony test method.
Prozone phenomenon
A condition where excess antibodies prevent precipitation, leading to unbound antibodies being detectable in the supernatant.
Serum Dilution
Remedy for Prozone phenomenon
Zone of Equivalence
The optimal mixing point of antigen and antibody where maximal precipitation occurs.
Postzone phenomenon
Occurs when excess antigens inhibit precipitation, leading to unbound antigens detectable in the supernatant.
Repeat the test after a week to give time for the antigen to reproduce.
Remedy for Postzone phenomenon
Immunoelectrophoresis
A technique combining electrophoresis with immunodiffusion to analyze serum proteins.
Rocket electrophoresis
One dimension, Electroimmunodiffusion technique.
It is a quick and simple in determining the concentration of specific antigens in a unknown sample.
The height of rocket is _______ to the concentration of antigen.
Directly proportional
Counterimmunoelectrophoresis (CIE)
Modification of Ouchterlony
Antigen and antibody puts onto the wells and Antibody migrates towards the cathode (-) and antigen to anode (+)
Grading of Agglutination
Smooth suspension
0
Grading of Agglutination
Barely discernible clumps
1+
Grading of Agglutination
numerous small clumps
2+
Grading of Agglutination
Several large clumps
3+
Grading of Agglutination
One solid clump
4+
Complement Fixation Test
A test that uses complement proteins to detect the presence of specific antibodies in a sample.
No Agglutination
The positive result for agglutination inhibition.
Agglutination
The negative result for Agglutination inhibition.
Indirect Antiglobulin Tests (IAT)
Identifies reactions of reagent RBC antigen with specific antibody when the reaction occurs in vitro.
Direct Antiglobulin test (DAT)
Detects specific antibodies or other serum proteins that bind to a px’s erythrocytes.
Labeled Immunoassay
A more specific and more sensitive compared to agglutination and precipitation reaction.
Referred to as receptor-ligand assays.
Fluorescent Antibody Test
A test that uses fluorescently labeled antibodies to detect specific antigens or antibodies.
Fluorescent isothiocyanate
Green fluorescence dye commonly used label in Fluorescent Antibody Test.
Tetramethyl Rhodamine
Red-orange fluorescence dye used for labeling.
phycocyanin
A red fluorescence dye used for labelling.
Fluorescence in situ Hybridization (FISH)
Test used to detecting and locating a specific DNA sequence on a metaphase chromosome and interphase of nucleus.
Competitive RIA
One of the most sensitive techniques for measuring hormones, drugs, and vitamins at concentration of <0.001.
Principle:
binding of radiolabeled Ag and unlabeled Ag to the limited supply of high affinity Ab.
Non-competitive RIA
Aka Sandwich Assay or IRMA
Bound radiolabeled Ab is directly proportional to the px’s Ag present in supernatant fluid.
Enzyme Immunoassay (EIA)
A technique that uses enzyme-labeled antibodies for the quantitative or qualitative measurement of antigens.
Western Blot
An analytical technique used to detect specific proteins in a sample, used as a confirmatory test for HIV.
PCR (Polymerase Chain Reaction)
A widely used method for amplifying specific DNA sequences.
Flow Cytometry
A technique for analyzing the physical and chemical characteristics of cells or particles suspended in a fluid.
Immunochromatography
A rapid test that employs antigen-antibody reactions, often used in point-of-care testing.
