Immunodiagnostics

Question 1

Western Blot

Answer 1

Used to Identify and determine the relative quantity of antigens or antibodies present in patient sample

Similar to ELISA except is more specific

Question 2

Nephelometry

Answer 2

Measuring immune complex formation in the liquid phase

amount of light scatter is measured and compared to a known amount scatter.
- helps determine types and concentrations of antibodies in a patient sample quickly. (Specifically IgM, IgG and IgA).

Question 3

Clinical uses for serology

Answer 3

Antibody/ antigen titers (autoimmunity)

Identification fo infections agents as well as the infection course

Diagnosis cancers

Question 4

Precipitation reactions

Answer 4

Double antigen and soluble antibody react and become insoluble for visualization

Question 5

Agglutination reactions

Answer 5

Soluble antibody reacts with an insoluble antigen attached to something and aggregates allowing for visualization
- the antigen or the attached product must be insoluble

IgM is the best antibody for agglutinate reactions because they have them spot receptors

Hemagglutination is a special type of agglutination reaction with red blood cells specifically

Question 6

Labeled immunoassays

Answer 6

Labels that emit lights/color are attached to antibodies or antigen

Light up and are visual when an antigen-antibody connection is made

Question 7

Coombs test

Answer 7

Type of hemagglutination to determine blood typing (indirect) and hemolytic anemia (direct)

Blood sample is taken and Coombs reagent is mixed with patients blood

If the patient has auto antibodies or antibodies for the Coombs reagent, agglutination will occur

Question 8

Indirect vs direct Coombs

Answer 8

Direct Coombs test is usually for hemolytic anemia where as indirect is for blood typing

Are the same tests except that indirect starts by taking patient serum containing antibodies and mixing them with donor blood. Then the Coombs reagent is added.

Direct does not use serum/plasma, indirect uses serum

Question 9

Slide agglutination

Answer 9

Quick agglutination reaction for blood typing

Blood is put on all wells of the slide and antibody reagent is added to the blood directly right there

(+) = no clumping and blood remains fluid looking (no condensation)

(-) = clumping and blood does not look fluid (condenses)

Question 10

Bacterial and latex agglutination

Answer 10

Less commonly used agglutination used to test for bacterial infections and latex allergies respectively

Bacterial agglutination = known bacterial cells mixed with patient serum
- if agglutination occurs, mean patients has that infection

Latex agglutination = latex beads are bound to antigens/antibodies and then placed in patient blood
- if agglutination occurs, means patient is allergic

Question 11

Agglutination inhibition

Answer 11

Opposite of normal where factory produced antibodies that are designed to cause agglutination are added to antigen coated beads and cause agglutination when patient antibodies are not present

Agglutination = negative for the patient antibodies

No agglutination = positive for the patient antibodies (since the patient antibodies outcompete with the factory agglutination antibodies)

Question 12

Hemagglutination well vs flat surface/card

Answer 12

Flat surface/card

• agglutination = condenses and forms a solid
• no agglutination = stays wide and liquid

Well

• agglutination = stays wide and liquid
• no agglutination = condenses and forms a solid

Question 13

Types of immunoassays used with fluorophores

Answer 13

Flow cytometry

Western blot

Immunoflurorescence microscopy

Question 14

Types of immunoassays using enzymes/substrates

Answer 14

ELISA

Western Blot

Question 15

Flow cytometry

Answer 15

Cells are stained with fluorescent-labeled antibodies to specific cell surface markers

Most common markers are CD3, CD$,CD* and CD20

Question 16

Direct vs indirect immunoflurorescence

Answer 16

Direct = primary antibody directly binds to the cells/tissues indicating presence of antigen

Indirect = secondary antibody binds to and indicates presence of primary antibody

Question 17

ELISA

Answer 17

Enzyme Linked Immunosorbent Assay

Enzymes conjugated with antibodies that produces a colorless substrate when not activated.
- when the enzyme is active = color is seen and indicates that the reagent for that enzyme is present in the sample

brighter the color = more of the reagent present

Used to test for HIV, drug tests, hormone tests, malaria etc.

Cheap and easy to sue

Question 18

3 ELISA types

Answer 18

Direct: primary antibody with enzyme binds to reagent directly
(Direct immunoassay)

Indirect: secondary antibody with enzyme binds to reagent indirectly
(Indirect immunoassay)

Sandwich: secondary antibody with enzyme binds to the reagent that is on a capture antibody, indirectly
(Indirect immunoassay)
* most potent one*