MICRO EXAM 2 CH10

Question 1

What occurs in an immunoassay between Ab-Ag?

Answer 1

An antibody molecule recognizes and binds to an antigen.

Question 2

What is binding of antibody and antigen related to?

Answer 2

Conc of each reactant.
Specificity of Ab to Ag.
Affinity and avidity.
Environmental conditions (temp, pH and time).

Question 3

Serology?

Answer 3

The study of serum.

Question 4

What is an antibody?

Answer 4

Proteins in the serum that bind to antigen.

Question 5

What is an antigen?

Answer 5

Anything that causes an immune response.
Usually a high molecular weight protein or polysaccharide.

Question 6

What is an immune complex?

Answer 6

Ab attached to an Ag.

Question 7

What is an immunogen?

Answer 7

The Ab-eliciting property of the molecule. (Is what triggers an immune response).

Question 8

What is an epitope?

Answer 8

A small part of a molecule that is recognized by the immune system.

Question 9

What is affinity?

Answer 9

The attraction between the Ab and Ag.

Question 10

What is high affinity binding?

Answer 10

Strong binding interaction between Ab and Ag.

Question 11

What is low affinity binding?

Answer 11

Weak binding interaction between Ab and Ag.

Question 12

What is avidity?

Answer 12

Overall strength of Ab-Ag bond that has been formed.

Question 13

Avidity and cross-reactivity relationship?

Answer 13

High avidity = low cross-reactivity and vice versa.

Question 14

What is the law of mass action?

Answer 14

Governs the reversibility of the Ab-Ag rxn.
At equilibrium, ratio between Ab and Ag remain constant.

Question 15

What are polyclonal Abs?

Answer 15

Mixture of multiple Ab that has been derived from different cells against multiple epitopes found on Ag(s).

Question 16

What are monoclonal Abs?

Answer 16

Only one cell that has been exposed to one epitope and specific to only one epitope.
High specificty and avidity.

Question 17

1st step of polyclonal Ab production?

Answer 17

Inject Ag into rabbit.

Question 18

2nd step of polyclonal Ab production?

Answer 18

Ag activates B cells.

Question 19

3rd step of polyclonal Ab production?

Answer 19

Plasma B cells produce polyclonal Abs.

Question 20

4th step of polyclonal Ab production?

Answer 20

Obtain antiserum from rabbit containing polyclonal Abs.

Question 21

1st step of monoclonal Ab production?

Answer 21

(Innocculation) Inject rabbit with antigen.

Question 22

2nd step of monoclonal Ab production?

Answer 22

(Innocculation) Obtain whole blood from rabbit, centrifuge for plasma.

Question 23

3rd step of monoclonal Ab production?

Answer 23

(Production) Mixing antiserum and myeloma cells to develop hybridoma cells.

Question 24

4th step of monoclonal Ab production?

Answer 24

Hybridomas are cloned for individual cells.

Question 25

5th step of monoclonal Ab production?

Answer 25

Test for monoclonal Abs.

Question 26

What is cross-reactivity?

Answer 26

When an antibody binds to an antigen that is not the exact target, but share similar epitopes.

Question 27

What immunoglobulin creates a primary response?

Answer 27

IgM

Question 28

What immunoglobulin creates a secondary response?

Answer 28

IgG *known as anamnestic response*

Question 29

What is a titer?

Answer 29

Measurement of the amount of Abs for specific Ags. *Highest or last dilution is the result*

Question 30

How is a titer reported?

Answer 30

1:16 dilution = 16

Question 31

How does an agglutination assay work?

Answer 31

Agglutinating Abs reacts with Ags on the surface of microscopic particles to form visible clumps.

Question 32

What are agglutination tests performed on?

Answer 32

Glass, plastic or cardboard slides. *Tubes as well*

Question 33

What is a direct agglutination?

Answer 33

Natural carrier particles of patient Ab and Ag.

Question 34

Example of direct agglutination?

Answer 34

RBCs, blood typing

Question 35

Example of indirect agglutination?

Answer 35

Latex beads coated with Ag.

Question 35

What is indirect agglutination?

Answer 35

Artificial carrier particles

Question 36

What is the prozone phenomenon in latex agglutination?

Answer 36

Occurs when the concentration of Abs exceeds the concentration of Ags. Also known as the zone of Ab excess.

Question 37

What is the postzone in latex agglutination?

Answer 37

Concentration of Ags exceed the Ab concentration.

Question 38

What kind of results can a postzone latex agglutination give?

Answer 38

False negs

Question 39

What is the zone of equivalence?

Answer 39

Optimal ratio of concentration between Ab and Ag.

Question 40

What is a labeled immunoassay?

Answer 40

Ag or Ab is labeled (tagged) with a substance that can be detected later on and allows for the detection of an antibody.

Question 41

Types of tags?

Answer 41

Radioactive isotopes (RIA) Enzymes (EMIT, ELISA) Fluorescent molecules Luminescent labels

Question 42

Types of immunoassays?

Answer 42

Heterogenous and homogenous

Question 43

What is heteogenous assays?

Answer 43

Separation assay that requires multiple steps.

Question 44

What is homogenous assays?

Answer 44

Does not require a separation step.

Question 45

What is a fluorescence polarization immunoassay?

Answer 45

It is a competitive and homogeneous assay.

Question 46

How does fluorescence polarization immunoassay work?

Answer 46

Ag (reagent) that is tagged and an untagged Ag (patient) compete for specific Ab in a cuvette.

Question 47

Results for fluorescence polarization immunosassay?

Answer 47

Larger molecules (tagged Ag) emit polarized light.

Question 48

What is luminescence/chemiluminescence?

Answer 48

Process of exciting molecules by chemical means and measuring the light emitted as the molecules turn back to their unexcited state. *Competitive and heterogeneous*

Question 49

What is direct fluorescent Ab test (DFA)?

Answer 49

A conjugated Ab to fluorescent tag binds to an Ag. Looks for Ag.

Question 50

Example of IFA?

Answer 50

FTA-ABS for syphillis

Question 51

What is indirect fluorescent Ab test (IFA)?

Answer 51

Ag fixed onto slide with primary Ab of interest (not tagged). Secondary Ab conjugated to fluorescent tag binds to primary Ab.

Question 52

What is immunofluorescent assays?

Answer 52

Rapid Ag or Ab detection. Mono or polyclonal Abs are conjugated with fluorochromes.

Question 53

What is competitive immunoassays?

Answer 53

Labeled known and patient unknown are added to a rxn to compete for the target.

Question 53

Examples of fluorochromes?

Answer 53

Fluorescien Rhadomine

Question 54

Is the concentration inversely proportional in a competitive immunoassay?

Answer 54

Yes

Question 55

What is a membrane-bound immunoassay?

Answer 55

An immunoassay that uses a membrane that has bound Abs.

Question 56

What is the material used for a membrane-bound immunoassay?

Answer 56

Nitrocelulose, nylon, etc

Question 57

What is an immunochromatographic test?

Answer 57

Detects Ag in lateral flow method. Abs bound to membrane.

Question 58

1st step of immunochromatographic test?

Answer 58

Specimen placed in buffer

Question 59

2nd step of immunochromatographic test?

Answer 59

Process sample is placed onto the membrane.

Question 60

3rd step of immunochromatographic test?

Answer 60

Buffer is carried laterally along the membrane by capillary action.

Question 61

4th step of immunochromatographic test?

Answer 61

Labeled rabbit Ab suspended in buffer.

Question 62

5th step of immunochromatographic test?

Answer 62

If Ag is present, Ag labeled Ab latex is formed = pos line