a science that attempts to detect signs of infection in a patient's serum such as Ab for specific microbe. Tests based on Abs specificially binding to Ag.
The most effective serological tests have high ________ and __________.
Specificity , Sensitivity
C. The binding of SPECIFIC Ab to a SPECIFIC Ag.
Lattice formation occurs in which phenomenom.
A. Secondary Phenomenon
It is the only one to have a visible reaction.
Which two sensitization phenomenons are not visible to the human eye.
Primary - binding of antibody to antigen - not visible
Tertiary - reaction not visible, but detected by affect of reaction on tissues or cells.
A. ability of test to give a positive result if the patient has the disease
D. ability of test to give negative result if patient does not have the disease..
C. Binding strength between Ag and Ab at the combinding site.
a. Binding strength between single Ag and single Ab combining site.
b. Overall binding strength of antigenic determinants and multivalent Ab.
c. And infinity and beyond.
d. Reaction strength between the Ab and Ag.
b. Overall binding strength of Ab determinants and Ag.
__________ affinity and ____________ avidity.
B. Monovalent, multivalent
Monovalent - single binding
Multivalent - more than one binding.
When you perform a serial dilution, what happens to the dilution factor and the concentration of the Antibody?
B. Higher dilution, lower concentration
Different dilutions of serum are tested with a constant amount of antigen. Which dilution is taken as the titer?
C. Highest reacting dilution
Ex: Perform a 1/2 dilution in a serial dilution. You perform a dilution 5 times. You see that the highest dilution is the 4th tube which is at a 1/16. That's the titer.
Development of detectable specific antibodies to pathogen in the serum as a result of infection or immunization.
What's the convalescent specimen in Testing Paired Samples?
The second specimen taken from the patient. It'll be compared to the acute specimen.
It'll show either the titer has raised (still fighting infection) or fallen (recovering).
Testing paired samples must see which rise in titer to be clinically significant?
A. 4 fold or 2 tube
Doctor's will believe that the infection is still strong. Further medication and therapy will be needed.
Law of Mass Action
Reversibility of the antigen-antibody reaction.
Visible reaction occurs when the rate of binding ________ the rate of dissociation.
B. Greater or exceeds
In the precipitation curve, which two zones has a invisible reactions and are capable of false negative results?
c. Zone of Equivalence
In the precipitation curve, the antibodies are an excess in the solution. The antibodies coat all antigen sites. It results in a false negative
In the precipitation curve, there's an antigen excess. The antibody coats antigen but no lattice formation. It results in false negative.
In the precipitation curve, the antigen and antibody present in optimal proportion to bind and give visible reaction.
A. Zone of Equivalence
Measurement of pricipitation by light is a qualitative or quantitative test?
EX: Turbidity and nephelometry
D. Measure the cloudiness
B. Indirect measurement, measures scattered light at an angle.
Turbidimetry is measured as what measurement?
a. Percent transmission
b. Opitcal density
A and B
Precipitation reaction in gels where Ab and Ag migrate towards each other. A precipitate forms where they meet in optimal proportions.
Pricipitation in solution. Single diffusion, single dimension.
A. Ab and Ag diffuse in a single dimension in the tube.
Radial immunodiffusion: Single diffusion in 2 dimensions.
Ouchterlony Gel Diffusion is a...
A. Double diffusion in 2 dimensions
Precipitate is a band.
In ouchterlony, the precipitation appears as a continuous line between the two Ag and one Anti-sera. It has no spurs or crossed lines. What does this mean?
d. One Ag well contains X and Y Ag, while the other Ag well contain just X Ag.
C. The two Ag are the same.
Band of identity
In ouchterlony, the precipitation band is formed between the two Ag and single Anti-sera well. The band has a spur and it's pointing at one of the Ag wells. What does this mean?
a. The two Ag are the same
b. The two Ag are different
c. The two Ag contain the same components but different concentrations.
d. One Ag well contains X and Y Ag, while the other Ag well contain just X Ag.
d. One Ag well contains X and Y Ag while the other contains only X Ag.
One well (XY Ag) contains an antigenic specificity not possessed by the other well (X Ag)
The spur points to the X Ag well.
In Ouchterlony, the precipitate band formed between the two Ag wells and single Anti-Sera well. The precipitate appears to be two crossed lines. What does this indicate?
D. The two Ag are different.
True or False: In Agglutination tests, Ab does not have to cross-link whole cell Ag.
It Ab must cross-link whole cell Ag, forming complexes that settle out and form visible clumps.
Ag found naturally on particle.
A. Direct Agglutination
Employs carrier particles (RBC, latex, betonite, charcoal) that are coated with soluble Ag. a. Passive Agglutination
b. Direct Agglutination
c. Reverse Passive Agglutination.
d. Agglutination Inhibition
a. Passive Agglutination
Remember soluble Ag!!!
Ab attached to carrier particle instead of Ag.
A. Reverse Passive Agglutination.
Measals virus naturally attaches to RBCs. If serum is added containing anti-measles Ab, attachment is blocked. Indicating that the patient's serum is positive. This test measures serum antibodies.
D. Agglutionation Inhibition
The detection of Ag by the aggregation of Ag and detector Ab attached to bacterial cell (staph/Protein A).
Remember the detector Ab is attached to a bacterial cell
This test detects Lysins- Ab that fix complement (complement capable of hemolyzing RBC). It involves mixing test Ag and Ab with complement and then with sensitized sheep RBC.
B. Complement fixation tests
(complement fixation test) If complement is fixed by the Ag-Ab, the RBCs remain intact the test is _______.
No lysis has occured since Complement binds to Ag/Ab.
(complement fixation test) if RBCs are hemolyzed, specific Ab are lacking and the test is ___________.
Complement ended up hemolyzing the RBC since it was not bound to a Ab/Ag
Diffusion combined with electrical current.
Ag is electrophoresed into gel containing Ab. The distance from starting well to the front of the rocket shaped arc is related to Ag concentration.
Migration of serum proteins in gel is combined with precipitation by Ab.
Antiserum is added to the trough, while the proteins are serum sample is at the starting well. Once the current is applied, the serum travels/migrates through the gel. Arcs form between the serum and anti-serum.
Proteins of sample are first seperated by electrophoresis in an agarose gel according to their gel. The gel is then overlaid with monospecific antisera reactive with specfic Ag. If they react, immunoprecipitin bands will form.
A. Immunofixation Electrophoresis
After electrophoresis, the gel is affixed to nitrocellulose blotting paper. The Ag is transferred to the blotter. The blotter is reacted with a test serum. The Ag and Ab complexes which form are detected using anti-human Ab reagent with a enzyme tag.
A. Western Blot test
Can detect unknown Ag or Ab by direct or indirect means. Detection of Ag-Ab complexes by tagged Ab with detection enzyme.
Direct EIA/immunoassay concept.
Used to measure Ag or Ab. Ag or Ab is bound to solid phase. Add known anti-Ab labeled with enzyme. Measure color change due to enzyme reaction with substrate.
Indirect EIA/immunoassay concept.
AKA Sandwich technique
A monocolonal Ab binds to the bacteria Ag. Ab tagged with detection enzyme recognize and binds to the monocolonal Ab. Measures color change due to enzyme reaction with the added substrate.
Capture Assay/ Immunoassay concept
Ab is attached to the titer plate. The attached Ab captures a monocolonal Ab. A detector anti-Ab recognize and binds to the monocolonal Ab. Enzyme and substrate reacts causing a color change.
Same concepts as Immunoassays, except the anti-Ab has fluorescence molecule attached not a detector enzyme.
Ab with (flo)fluorescence tag binds to a killer T cell or Helper T cell. The cell is sent through a machine, and lasers are shot through the machine. The lazers are absorbed by the flo tags and they emit fluorescent lighting which is measured by the detector.